File: test_all.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
import io
import unittest

import torch
from torch import nn, Tensor
from typing import List

from models.matcher import HungarianMatcher
from models.position_encoding import PositionEmbeddingSine, PositionEmbeddingLearned
from models.backbone import Backbone, Joiner, BackboneBase
from util import box_ops
from util.misc import nested_tensor_from_tensor_list
from hubconf import detr_resnet50, detr_resnet50_panoptic

# onnxruntime requires python 3.5 or above
try:
    import onnxruntime
except ImportError:
    onnxruntime = None


class Tester(unittest.TestCase):

    def test_box_cxcywh_to_xyxy(self):
        t = torch.rand(10, 4)
        r = box_ops.box_xyxy_to_cxcywh(box_ops.box_cxcywh_to_xyxy(t))
        self.assertLess((t - r).abs().max(), 1e-5)

    @staticmethod
    def indices_torch2python(indices):
        return [(i.tolist(), j.tolist()) for i, j in indices]

    def test_hungarian(self):
        n_queries, n_targets, n_classes = 100, 15, 91
        logits = torch.rand(1, n_queries, n_classes + 1)
        boxes = torch.rand(1, n_queries, 4)
        tgt_labels = torch.randint(high=n_classes, size=(n_targets,))
        tgt_boxes = torch.rand(n_targets, 4)
        matcher = HungarianMatcher()
        targets = [{'labels': tgt_labels, 'boxes': tgt_boxes}]
        indices_single = matcher({'pred_logits': logits, 'pred_boxes': boxes}, targets)
        indices_batched = matcher({'pred_logits': logits.repeat(2, 1, 1),
                                   'pred_boxes': boxes.repeat(2, 1, 1)}, targets * 2)
        self.assertEqual(len(indices_single[0][0]), n_targets)
        self.assertEqual(len(indices_single[0][1]), n_targets)
        self.assertEqual(self.indices_torch2python(indices_single),
                         self.indices_torch2python([indices_batched[0]]))
        self.assertEqual(self.indices_torch2python(indices_single),
                         self.indices_torch2python([indices_batched[1]]))

        # test with empty targets
        tgt_labels_empty = torch.randint(high=n_classes, size=(0,))
        tgt_boxes_empty = torch.rand(0, 4)
        targets_empty = [{'labels': tgt_labels_empty, 'boxes': tgt_boxes_empty}]
        indices = matcher({'pred_logits': logits.repeat(2, 1, 1),
                           'pred_boxes': boxes.repeat(2, 1, 1)}, targets + targets_empty)
        self.assertEqual(len(indices[1][0]), 0)
        indices = matcher({'pred_logits': logits.repeat(2, 1, 1),
                           'pred_boxes': boxes.repeat(2, 1, 1)}, targets_empty * 2)
        self.assertEqual(len(indices[0][0]), 0)

    def test_position_encoding_script(self):
        m1, m2 = PositionEmbeddingSine(), PositionEmbeddingLearned()
        mm1, mm2 = torch.jit.script(m1), torch.jit.script(m2)  # noqa

    def test_backbone_script(self):
        backbone = Backbone('resnet50', True, False, False)
        torch.jit.script(backbone)  # noqa

    def test_model_script_detection(self):
        model = detr_resnet50(pretrained=False).eval()
        scripted_model = torch.jit.script(model)
        x = nested_tensor_from_tensor_list([torch.rand(3, 200, 200), torch.rand(3, 200, 250)])
        out = model(x)
        out_script = scripted_model(x)
        self.assertTrue(out["pred_logits"].equal(out_script["pred_logits"]))
        self.assertTrue(out["pred_boxes"].equal(out_script["pred_boxes"]))

    def test_model_script_panoptic(self):
        model = detr_resnet50_panoptic(pretrained=False).eval()
        scripted_model = torch.jit.script(model)
        x = nested_tensor_from_tensor_list([torch.rand(3, 200, 200), torch.rand(3, 200, 250)])
        out = model(x)
        out_script = scripted_model(x)
        self.assertTrue(out["pred_logits"].equal(out_script["pred_logits"]))
        self.assertTrue(out["pred_boxes"].equal(out_script["pred_boxes"]))
        self.assertTrue(out["pred_masks"].equal(out_script["pred_masks"]))

    def test_model_detection_different_inputs(self):
        model = detr_resnet50(pretrained=False).eval()
        # support NestedTensor
        x = nested_tensor_from_tensor_list([torch.rand(3, 200, 200), torch.rand(3, 200, 250)])
        out = model(x)
        self.assertIn('pred_logits', out)
        # and 4d Tensor
        x = torch.rand(1, 3, 200, 200)
        out = model(x)
        self.assertIn('pred_logits', out)
        # and List[Tensor[C, H, W]]
        x = torch.rand(3, 200, 200)
        out = model([x])
        self.assertIn('pred_logits', out)

    def test_warpped_model_script_detection(self):
        class WrappedDETR(nn.Module):
            def __init__(self, model):
                super().__init__()
                self.model = model

            def forward(self, inputs: List[Tensor]):
                sample = nested_tensor_from_tensor_list(inputs)
                return self.model(sample)

        model = detr_resnet50(pretrained=False)
        wrapped_model = WrappedDETR(model)
        wrapped_model.eval()
        scripted_model = torch.jit.script(wrapped_model)
        x = [torch.rand(3, 200, 200), torch.rand(3, 200, 250)]
        out = wrapped_model(x)
        out_script = scripted_model(x)
        self.assertTrue(out["pred_logits"].equal(out_script["pred_logits"]))
        self.assertTrue(out["pred_boxes"].equal(out_script["pred_boxes"]))


@unittest.skipIf(onnxruntime is None, 'ONNX Runtime unavailable')
class ONNXExporterTester(unittest.TestCase):
    @classmethod
    def setUpClass(cls):
        torch.manual_seed(123)

    def run_model(self, model, inputs_list, tolerate_small_mismatch=False, do_constant_folding=True, dynamic_axes=None,
                  output_names=None, input_names=None):
        model.eval()

        onnx_io = io.BytesIO()
        # export to onnx with the first input
        torch.onnx.export(model, inputs_list[0], onnx_io,
                          do_constant_folding=do_constant_folding, opset_version=12,
                          dynamic_axes=dynamic_axes, input_names=input_names, output_names=output_names)
        # validate the exported model with onnx runtime
        for test_inputs in inputs_list:
            with torch.no_grad():
                if isinstance(test_inputs, torch.Tensor) or isinstance(test_inputs, list):
                    test_inputs = (nested_tensor_from_tensor_list(test_inputs),)
                test_ouputs = model(*test_inputs)
                if isinstance(test_ouputs, torch.Tensor):
                    test_ouputs = (test_ouputs,)
            self.ort_validate(onnx_io, test_inputs, test_ouputs, tolerate_small_mismatch)

    def ort_validate(self, onnx_io, inputs, outputs, tolerate_small_mismatch=False):

        inputs, _ = torch.jit._flatten(inputs)
        outputs, _ = torch.jit._flatten(outputs)

        def to_numpy(tensor):
            if tensor.requires_grad:
                return tensor.detach().cpu().numpy()
            else:
                return tensor.cpu().numpy()

        inputs = list(map(to_numpy, inputs))
        outputs = list(map(to_numpy, outputs))

        ort_session = onnxruntime.InferenceSession(onnx_io.getvalue())
        # compute onnxruntime output prediction
        ort_inputs = dict((ort_session.get_inputs()[i].name, inpt) for i, inpt in enumerate(inputs))
        ort_outs = ort_session.run(None, ort_inputs)
        for i, element in enumerate(outputs):
            try:
                torch.testing.assert_allclose(element, ort_outs[i], rtol=1e-03, atol=1e-05)
            except AssertionError as error:
                if tolerate_small_mismatch:
                    self.assertIn("(0.00%)", str(error), str(error))
                else:
                    raise

    def test_model_onnx_detection(self):
        model = detr_resnet50(pretrained=False).eval()
        dummy_image = torch.ones(1, 3, 800, 800) * 0.3
        model(dummy_image)

        # Test exported model on images of different size, or dummy input
        self.run_model(
            model,
            [(torch.rand(1, 3, 750, 800),)],
            input_names=["inputs"],
            output_names=["pred_logits", "pred_boxes"],
            tolerate_small_mismatch=True,
        )

    @unittest.skip("CI doesn't have enough memory")
    def test_model_onnx_detection_panoptic(self):
        model = detr_resnet50_panoptic(pretrained=False).eval()
        dummy_image = torch.ones(1, 3, 800, 800) * 0.3
        model(dummy_image)

        # Test exported model on images of different size, or dummy input
        self.run_model(
            model,
            [(torch.rand(1, 3, 750, 800),)],
            input_names=["inputs"],
            output_names=["pred_logits", "pred_boxes", "pred_masks"],
            tolerate_small_mismatch=True,
        )


if __name__ == '__main__':
    unittest.main()



File: run_with_submitit.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
A script to run multinode training with submitit.
"""
import argparse
import os
import uuid
from pathlib import Path

import main as detection
import submitit


def parse_args():
    detection_parser = detection.get_args_parser()
    parser = argparse.ArgumentParser("Submitit for detection", parents=[detection_parser])
    parser.add_argument("--ngpus", default=8, type=int, help="Number of gpus to request on each node")
    parser.add_argument("--nodes", default=4, type=int, help="Number of nodes to request")
    parser.add_argument("--timeout", default=60, type=int, help="Duration of the job")
    parser.add_argument("--job_dir", default="", type=str, help="Job dir. Leave empty for automatic.")
    return parser.parse_args()


def get_shared_folder() -> Path:
    user = os.getenv("USER")
    if Path("/checkpoint/").is_dir():
        p = Path(f"/checkpoint/{user}/experiments")
        p.mkdir(exist_ok=True)
        return p
    raise RuntimeError("No shared folder available")


def get_init_file():
    # Init file must not exist, but it's parent dir must exist.
    os.makedirs(str(get_shared_folder()), exist_ok=True)
    init_file = get_shared_folder() / f"{uuid.uuid4().hex}_init"
    if init_file.exists():
        os.remove(str(init_file))
    return init_file


class Trainer(object):
    def __init__(self, args):
        self.args = args

    def __call__(self):
        import main as detection

        self._setup_gpu_args()
        detection.main(self.args)

    def checkpoint(self):
        import os
        import submitit
        from pathlib import Path

        self.args.dist_url = get_init_file().as_uri()
        checkpoint_file = os.path.join(self.args.output_dir, "checkpoint.pth")
        if os.path.exists(checkpoint_file):
            self.args.resume = checkpoint_file
        print("Requeuing ", self.args)
        empty_trainer = type(self)(self.args)
        return submitit.helpers.DelayedSubmission(empty_trainer)

    def _setup_gpu_args(self):
        import submitit
        from pathlib import Path

        job_env = submitit.JobEnvironment()
        self.args.output_dir = Path(str(self.args.output_dir).replace("%j", str(job_env.job_id)))
        self.args.gpu = job_env.local_rank
        self.args.rank = job_env.global_rank
        self.args.world_size = job_env.num_tasks
        print(f"Process group: {job_env.num_tasks} tasks, rank: {job_env.global_rank}")


def main():
    args = parse_args()
    if args.job_dir == "":
        args.job_dir = get_shared_folder() / "%j"

    # Note that the folder will depend on the job_id, to easily track experiments
    executor = submitit.AutoExecutor(folder=args.job_dir, slurm_max_num_timeout=30)

    # cluster setup is defined by environment variables
    num_gpus_per_node = args.ngpus
    nodes = args.nodes
    timeout_min = args.timeout

    executor.update_parameters(
        mem_gb=40 * num_gpus_per_node,
        gpus_per_node=num_gpus_per_node,
        tasks_per_node=num_gpus_per_node,  # one task per GPU
        cpus_per_task=10,
        nodes=nodes,
        timeout_min=timeout_min,  # max is 60 * 72
    )

    executor.update_parameters(name="detr")

    args.dist_url = get_init_file().as_uri()
    args.output_dir = args.job_dir

    trainer = Trainer(args)
    job = executor.submit(trainer)

    print("Submitted job_id:", job.job_id)


if __name__ == "__main__":
    main()



File: engine.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
Train and eval functions used in main.py
"""
import math
import os
import sys
from typing import Iterable

import torch

import util.misc as utils
from datasets.coco_eval import CocoEvaluator
from datasets.panoptic_eval import PanopticEvaluator


def train_one_epoch(model: torch.nn.Module, criterion: torch.nn.Module,
                    data_loader: Iterable, optimizer: torch.optim.Optimizer,
                    device: torch.device, epoch: int, max_norm: float = 0):
    model.train()
    criterion.train()
    metric_logger = utils.MetricLogger(delimiter="  ")
    metric_logger.add_meter('lr', utils.SmoothedValue(window_size=1, fmt='{value:.6f}'))
    metric_logger.add_meter('class_error', utils.SmoothedValue(window_size=1, fmt='{value:.2f}'))
    header = 'Epoch: [{}]'.format(epoch)
    print_freq = 10

    for samples, targets in metric_logger.log_every(data_loader, print_freq, header):
        samples = samples.to(device)
        targets = [{k: v.to(device) for k, v in t.items()} for t in targets]

        outputs = model(samples)
        loss_dict = criterion(outputs, targets)
        weight_dict = criterion.weight_dict
        losses = sum(loss_dict[k] * weight_dict[k] for k in loss_dict.keys() if k in weight_dict)

        # reduce losses over all GPUs for logging purposes
        loss_dict_reduced = utils.reduce_dict(loss_dict)
        loss_dict_reduced_unscaled = {f'{k}_unscaled': v
                                      for k, v in loss_dict_reduced.items()}
        loss_dict_reduced_scaled = {k: v * weight_dict[k]
                                    for k, v in loss_dict_reduced.items() if k in weight_dict}
        losses_reduced_scaled = sum(loss_dict_reduced_scaled.values())

        loss_value = losses_reduced_scaled.item()

        if not math.isfinite(loss_value):
            print("Loss is {}, stopping training".format(loss_value))
            print(loss_dict_reduced)
            sys.exit(1)

        optimizer.zero_grad()
        losses.backward()
        if max_norm > 0:
            torch.nn.utils.clip_grad_norm_(model.parameters(), max_norm)
        optimizer.step()

        metric_logger.update(loss=loss_value, **loss_dict_reduced_scaled, **loss_dict_reduced_unscaled)
        metric_logger.update(class_error=loss_dict_reduced['class_error'])
        metric_logger.update(lr=optimizer.param_groups[0]["lr"])
    # gather the stats from all processes
    metric_logger.synchronize_between_processes()
    print("Averaged stats:", metric_logger)
    return {k: meter.global_avg for k, meter in metric_logger.meters.items()}


@torch.no_grad()
def evaluate(model, criterion, postprocessors, data_loader, base_ds, device, output_dir):
    model.eval()
    criterion.eval()

    metric_logger = utils.MetricLogger(delimiter="  ")
    metric_logger.add_meter('class_error', utils.SmoothedValue(window_size=1, fmt='{value:.2f}'))
    header = 'Test:'

    iou_types = tuple(k for k in ('segm', 'bbox') if k in postprocessors.keys())
    coco_evaluator = CocoEvaluator(base_ds, iou_types)
    # coco_evaluator.coco_eval[iou_types[0]].params.iouThrs = [0, 0.1, 0.5, 0.75]

    panoptic_evaluator = None
    if 'panoptic' in postprocessors.keys():
        panoptic_evaluator = PanopticEvaluator(
            data_loader.dataset.ann_file,
            data_loader.dataset.ann_folder,
            output_dir=os.path.join(output_dir, "panoptic_eval"),
        )

    for samples, targets in metric_logger.log_every(data_loader, 10, header):
        samples = samples.to(device)
        targets = [{k: v.to(device) for k, v in t.items()} for t in targets]

        outputs = model(samples)
        loss_dict = criterion(outputs, targets)
        weight_dict = criterion.weight_dict

        # reduce losses over all GPUs for logging purposes
        loss_dict_reduced = utils.reduce_dict(loss_dict)
        loss_dict_reduced_scaled = {k: v * weight_dict[k]
                                    for k, v in loss_dict_reduced.items() if k in weight_dict}
        loss_dict_reduced_unscaled = {f'{k}_unscaled': v
                                      for k, v in loss_dict_reduced.items()}
        metric_logger.update(loss=sum(loss_dict_reduced_scaled.values()),
                             **loss_dict_reduced_scaled,
                             **loss_dict_reduced_unscaled)
        metric_logger.update(class_error=loss_dict_reduced['class_error'])

        orig_target_sizes = torch.stack([t["orig_size"] for t in targets], dim=0)
        results = postprocessors['bbox'](outputs, orig_target_sizes)
        if 'segm' in postprocessors.keys():
            target_sizes = torch.stack([t["size"] for t in targets], dim=0)
            results = postprocessors['segm'](results, outputs, orig_target_sizes, target_sizes)
        res = {target['image_id'].item(): output for target, output in zip(targets, results)}
        if coco_evaluator is not None:
            coco_evaluator.update(res)

        if panoptic_evaluator is not None:
            res_pano = postprocessors["panoptic"](outputs, target_sizes, orig_target_sizes)
            for i, target in enumerate(targets):
                image_id = target["image_id"].item()
                file_name = f"{image_id:012d}.png"
                res_pano[i]["image_id"] = image_id
                res_pano[i]["file_name"] = file_name

            panoptic_evaluator.update(res_pano)

    # gather the stats from all processes
    metric_logger.synchronize_between_processes()
    print("Averaged stats:", metric_logger)
    if coco_evaluator is not None:
        coco_evaluator.synchronize_between_processes()
    if panoptic_evaluator is not None:
        panoptic_evaluator.synchronize_between_processes()

    # accumulate predictions from all images
    if coco_evaluator is not None:
        coco_evaluator.accumulate()
        coco_evaluator.summarize()
    panoptic_res = None
    if panoptic_evaluator is not None:
        panoptic_res = panoptic_evaluator.summarize()
    stats = {k: meter.global_avg for k, meter in metric_logger.meters.items()}
    if coco_evaluator is not None:
        if 'bbox' in postprocessors.keys():
            stats['coco_eval_bbox'] = coco_evaluator.coco_eval['bbox'].stats.tolist()
        if 'segm' in postprocessors.keys():
            stats['coco_eval_masks'] = coco_evaluator.coco_eval['segm'].stats.tolist()
    if panoptic_res is not None:
        stats['PQ_all'] = panoptic_res["All"]
        stats['PQ_th'] = panoptic_res["Things"]
        stats['PQ_st'] = panoptic_res["Stuff"]
    return stats, coco_evaluator



File: hubconf.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
import torch

from models.backbone import Backbone, Joiner
from models.detr import DETR, PostProcess
from models.position_encoding import PositionEmbeddingSine
from models.segmentation import DETRsegm, PostProcessPanoptic
from models.transformer import Transformer

dependencies = ["torch", "torchvision"]


def _make_detr(backbone_name: str, dilation=False, num_classes=91, mask=False):
    hidden_dim = 256
    backbone = Backbone(backbone_name, train_backbone=True, return_interm_layers=mask, dilation=dilation)
    pos_enc = PositionEmbeddingSine(hidden_dim // 2, normalize=True)
    backbone_with_pos_enc = Joiner(backbone, pos_enc)
    backbone_with_pos_enc.num_channels = backbone.num_channels
    transformer = Transformer(d_model=hidden_dim, return_intermediate_dec=True)
    detr = DETR(backbone_with_pos_enc, transformer, num_classes=num_classes, num_queries=100)
    if mask:
        return DETRsegm(detr)
    return detr


def detr_resnet50(pretrained=False, num_classes=91, return_postprocessor=False):
    """
    DETR R50 with 6 encoder and 6 decoder layers.

    Achieves 42/62.4 AP/AP50 on COCO val5k.
    """
    model = _make_detr("resnet50", dilation=False, num_classes=num_classes)
    if pretrained:
        checkpoint = torch.hub.load_state_dict_from_url(
            url="https://dl.fbaipublicfiles.com/detr/detr-r50-e632da11.pth", map_location="cpu", check_hash=True
        )
        model.load_state_dict(checkpoint["model"])
    if return_postprocessor:
        return model, PostProcess()
    return model


def detr_resnet50_dc5(pretrained=False, num_classes=91, return_postprocessor=False):
    """
    DETR-DC5 R50 with 6 encoder and 6 decoder layers.

    The last block of ResNet-50 has dilation to increase
    output resolution.
    Achieves 43.3/63.1 AP/AP50 on COCO val5k.
    """
    model = _make_detr("resnet50", dilation=True, num_classes=num_classes)
    if pretrained:
        checkpoint = torch.hub.load_state_dict_from_url(
            url="https://dl.fbaipublicfiles.com/detr/detr-r50-dc5-f0fb7ef5.pth", map_location="cpu", check_hash=True
        )
        model.load_state_dict(checkpoint["model"])
    if return_postprocessor:
        return model, PostProcess()
    return model


def detr_resnet101(pretrained=False, num_classes=91, return_postprocessor=False):
    """
    DETR-DC5 R101 with 6 encoder and 6 decoder layers.

    Achieves 43.5/63.8 AP/AP50 on COCO val5k.
    """
    model = _make_detr("resnet101", dilation=False, num_classes=num_classes)
    if pretrained:
        checkpoint = torch.hub.load_state_dict_from_url(
            url="https://dl.fbaipublicfiles.com/detr/detr-r101-2c7b67e5.pth", map_location="cpu", check_hash=True
        )
        model.load_state_dict(checkpoint["model"])
    if return_postprocessor:
        return model, PostProcess()
    return model


def detr_resnet101_dc5(pretrained=False, num_classes=91, return_postprocessor=False):
    """
    DETR-DC5 R101 with 6 encoder and 6 decoder layers.

    The last block of ResNet-101 has dilation to increase
    output resolution.
    Achieves 44.9/64.7 AP/AP50 on COCO val5k.
    """
    model = _make_detr("resnet101", dilation=True, num_classes=num_classes)
    if pretrained:
        checkpoint = torch.hub.load_state_dict_from_url(
            url="https://dl.fbaipublicfiles.com/detr/detr-r101-dc5-a2e86def.pth", map_location="cpu", check_hash=True
        )
        model.load_state_dict(checkpoint["model"])
    if return_postprocessor:
        return model, PostProcess()
    return model


def detr_resnet50_panoptic(
    pretrained=False, num_classes=250, threshold=0.85, return_postprocessor=False
):
    """
    DETR R50 with 6 encoder and 6 decoder layers.
    Achieves 43.4 PQ on COCO val5k.

   threshold is the minimum confidence required for keeping segments in the prediction
    """
    model = _make_detr("resnet50", dilation=False, num_classes=num_classes, mask=True)
    is_thing_map = {i: i <= 90 for i in range(250)}
    if pretrained:
        checkpoint = torch.hub.load_state_dict_from_url(
            url="https://dl.fbaipublicfiles.com/detr/detr-r50-panoptic-00ce5173.pth",
            map_location="cpu",
            check_hash=True,
        )
        model.load_state_dict(checkpoint["model"])
    if return_postprocessor:
        return model, PostProcessPanoptic(is_thing_map, threshold=threshold)
    return model


def detr_resnet50_dc5_panoptic(
    pretrained=False, num_classes=250, threshold=0.85, return_postprocessor=False
):
    """
    DETR-DC5 R50 with 6 encoder and 6 decoder layers.

    The last block of ResNet-50 has dilation to increase
    output resolution.
    Achieves 44.6 on COCO val5k.

   threshold is the minimum confidence required for keeping segments in the prediction
    """
    model = _make_detr("resnet50", dilation=True, num_classes=num_classes, mask=True)
    is_thing_map = {i: i <= 90 for i in range(250)}
    if pretrained:
        checkpoint = torch.hub.load_state_dict_from_url(
            url="https://dl.fbaipublicfiles.com/detr/detr-r50-dc5-panoptic-da08f1b1.pth",
            map_location="cpu",
            check_hash=True,
        )
        model.load_state_dict(checkpoint["model"])
    if return_postprocessor:
        return model, PostProcessPanoptic(is_thing_map, threshold=threshold)
    return model


def detr_resnet101_panoptic(
    pretrained=False, num_classes=250, threshold=0.85, return_postprocessor=False
):
    """
    DETR-DC5 R101 with 6 encoder and 6 decoder layers.

    Achieves 45.1 PQ on COCO val5k.

   threshold is the minimum confidence required for keeping segments in the prediction
    """
    model = _make_detr("resnet101", dilation=False, num_classes=num_classes, mask=True)
    is_thing_map = {i: i <= 90 for i in range(250)}
    if pretrained:
        checkpoint = torch.hub.load_state_dict_from_url(
            url="https://dl.fbaipublicfiles.com/detr/detr-r101-panoptic-40021d53.pth",
            map_location="cpu",
            check_hash=True,
        )
        model.load_state_dict(checkpoint["model"])
    if return_postprocessor:
        return model, PostProcessPanoptic(is_thing_map, threshold=threshold)
    return model



File: main.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
import argparse
import datetime
import json
import random
import time
from pathlib import Path

import numpy as np
import torch
from torch.utils.data import DataLoader, DistributedSampler

import datasets
import util.misc as utils
from datasets import build_dataset, get_coco_api_from_dataset
from engine import evaluate, train_one_epoch
from models import build_model


def get_args_parser():
    parser = argparse.ArgumentParser('Set transformer detector', add_help=False)
    parser.add_argument('--lr', default=1e-4, type=float)
    parser.add_argument('--lr_backbone', default=1e-5, type=float)
    parser.add_argument('--batch_size', default=2, type=int)
    parser.add_argument('--weight_decay', default=1e-4, type=float)
    parser.add_argument('--epochs', default=300, type=int)
    parser.add_argument('--lr_drop', default=200, type=int)
    parser.add_argument('--clip_max_norm', default=0.1, type=float,
                        help='gradient clipping max norm')

    # Model parameters
    parser.add_argument('--frozen_weights', type=str, default=None,
                        help="Path to the pretrained model. If set, only the mask head will be trained")
    # * Backbone
    parser.add_argument('--backbone', default='resnet50', type=str,
                        help="Name of the convolutional backbone to use")
    parser.add_argument('--dilation', action='store_true',
                        help="If true, we replace stride with dilation in the last convolutional block (DC5)")
    parser.add_argument('--position_embedding', default='sine', type=str, choices=('sine', 'learned'),
                        help="Type of positional embedding to use on top of the image features")

    # * Transformer
    parser.add_argument('--enc_layers', default=6, type=int,
                        help="Number of encoding layers in the transformer")
    parser.add_argument('--dec_layers', default=6, type=int,
                        help="Number of decoding layers in the transformer")
    parser.add_argument('--dim_feedforward', default=2048, type=int,
                        help="Intermediate size of the feedforward layers in the transformer blocks")
    parser.add_argument('--hidden_dim', default=256, type=int,
                        help="Size of the embeddings (dimension of the transformer)")
    parser.add_argument('--dropout', default=0.1, type=float,
                        help="Dropout applied in the transformer")
    parser.add_argument('--nheads', default=8, type=int,
                        help="Number of attention heads inside the transformer's attentions")
    parser.add_argument('--num_queries', default=100, type=int,
                        help="Number of query slots")
    parser.add_argument('--pre_norm', action='store_true')

    # * Segmentation
    parser.add_argument('--masks', action='store_true',
                        help="Train segmentation head if the flag is provided")

    # Loss
    parser.add_argument('--no_aux_loss', dest='aux_loss', action='store_false',
                        help="Disables auxiliary decoding losses (loss at each layer)")
    # * Matcher
    parser.add_argument('--set_cost_class', default=1, type=float,
                        help="Class coefficient in the matching cost")
    parser.add_argument('--set_cost_bbox', default=5, type=float,
                        help="L1 box coefficient in the matching cost")
    parser.add_argument('--set_cost_giou', default=2, type=float,
                        help="giou box coefficient in the matching cost")
    # * Loss coefficients
    parser.add_argument('--mask_loss_coef', default=1, type=float)
    parser.add_argument('--dice_loss_coef', default=1, type=float)
    parser.add_argument('--bbox_loss_coef', default=5, type=float)
    parser.add_argument('--giou_loss_coef', default=2, type=float)
    parser.add_argument('--eos_coef', default=0.1, type=float,
                        help="Relative classification weight of the no-object class")

    # dataset parameters
    parser.add_argument('--dataset_file', default='coco')
    parser.add_argument('--coco_path', type=str)
    parser.add_argument('--coco_panoptic_path', type=str)
    parser.add_argument('--remove_difficult', action='store_true')

    parser.add_argument('--output_dir', default='',
                        help='path where to save, empty for no saving')
    parser.add_argument('--device', default='cuda',
                        help='device to use for training / testing')
    parser.add_argument('--seed', default=42, type=int)
    parser.add_argument('--resume', default='', help='resume from checkpoint')
    parser.add_argument('--start_epoch', default=0, type=int, metavar='N',
                        help='start epoch')
    parser.add_argument('--eval', action='store_true')
    parser.add_argument('--num_workers', default=2, type=int)

    # distributed training parameters
    parser.add_argument('--world_size', default=1, type=int,
                        help='number of distributed processes')
    parser.add_argument('--dist_url', default='env://', help='url used to set up distributed training')
    return parser


def main(args):
    utils.init_distributed_mode(args)
    print("git:\n  {}\n".format(utils.get_sha()))

    if args.frozen_weights is not None:
        assert args.masks, "Frozen training is meant for segmentation only"
    print(args)

    device = torch.device(args.device)

    # fix the seed for reproducibility
    seed = args.seed + utils.get_rank()
    torch.manual_seed(seed)
    np.random.seed(seed)
    random.seed(seed)

    model, criterion, postprocessors = build_model(args)
    model.to(device)

    model_without_ddp = model
    if args.distributed:
        model = torch.nn.parallel.DistributedDataParallel(model, device_ids=[args.gpu])
        model_without_ddp = model.module
    n_parameters = sum(p.numel() for p in model.parameters() if p.requires_grad)
    print('number of params:', n_parameters)

    param_dicts = [
        {"params": [p for n, p in model_without_ddp.named_parameters() if "backbone" not in n and p.requires_grad]},
        {
            "params": [p for n, p in model_without_ddp.named_parameters() if "backbone" in n and p.requires_grad],
            "lr": args.lr_backbone,
        },
    ]
    optimizer = torch.optim.AdamW(param_dicts, lr=args.lr,
                                  weight_decay=args.weight_decay)
    lr_scheduler = torch.optim.lr_scheduler.StepLR(optimizer, args.lr_drop)

    dataset_train = build_dataset(image_set='train', args=args)
    dataset_val = build_dataset(image_set='val', args=args)

    if args.distributed:
        sampler_train = DistributedSampler(dataset_train)
        sampler_val = DistributedSampler(dataset_val, shuffle=False)
    else:
        sampler_train = torch.utils.data.RandomSampler(dataset_train)
        sampler_val = torch.utils.data.SequentialSampler(dataset_val)

    batch_sampler_train = torch.utils.data.BatchSampler(
        sampler_train, args.batch_size, drop_last=True)

    data_loader_train = DataLoader(dataset_train, batch_sampler=batch_sampler_train,
                                   collate_fn=utils.collate_fn, num_workers=args.num_workers)
    data_loader_val = DataLoader(dataset_val, args.batch_size, sampler=sampler_val,
                                 drop_last=False, collate_fn=utils.collate_fn, num_workers=args.num_workers)

    if args.dataset_file == "coco_panoptic":
        # We also evaluate AP during panoptic training, on original coco DS
        coco_val = datasets.coco.build("val", args)
        base_ds = get_coco_api_from_dataset(coco_val)
    else:
        base_ds = get_coco_api_from_dataset(dataset_val)

    if args.frozen_weights is not None:
        checkpoint = torch.load(args.frozen_weights, map_location='cpu')
        model_without_ddp.detr.load_state_dict(checkpoint['model'])

    output_dir = Path(args.output_dir)
    if args.resume:
        if args.resume.startswith('https'):
            checkpoint = torch.hub.load_state_dict_from_url(
                args.resume, map_location='cpu', check_hash=True)
        else:
            checkpoint = torch.load(args.resume, map_location='cpu')
        model_without_ddp.load_state_dict(checkpoint['model'])
        if not args.eval and 'optimizer' in checkpoint and 'lr_scheduler' in checkpoint and 'epoch' in checkpoint:
            optimizer.load_state_dict(checkpoint['optimizer'])
            lr_scheduler.load_state_dict(checkpoint['lr_scheduler'])
            args.start_epoch = checkpoint['epoch'] + 1

    if args.eval:
        test_stats, coco_evaluator = evaluate(model, criterion, postprocessors,
                                              data_loader_val, base_ds, device, args.output_dir)
        if args.output_dir:
            utils.save_on_master(coco_evaluator.coco_eval["bbox"].eval, output_dir / "eval.pth")
        return

    print("Start training")
    start_time = time.time()
    for epoch in range(args.start_epoch, args.epochs):
        if args.distributed:
            sampler_train.set_epoch(epoch)
        train_stats = train_one_epoch(
            model, criterion, data_loader_train, optimizer, device, epoch,
            args.clip_max_norm)
        lr_scheduler.step()
        if args.output_dir:
            checkpoint_paths = [output_dir / 'checkpoint.pth']
            # extra checkpoint before LR drop and every 100 epochs
            if (epoch + 1) % args.lr_drop == 0 or (epoch + 1) % 100 == 0:
                checkpoint_paths.append(output_dir / f'checkpoint{epoch:04}.pth')
            for checkpoint_path in checkpoint_paths:
                utils.save_on_master({
                    'model': model_without_ddp.state_dict(),
                    'optimizer': optimizer.state_dict(),
                    'lr_scheduler': lr_scheduler.state_dict(),
                    'epoch': epoch,
                    'args': args,
                }, checkpoint_path)

        test_stats, coco_evaluator = evaluate(
            model, criterion, postprocessors, data_loader_val, base_ds, device, args.output_dir
        )

        log_stats = {**{f'train_{k}': v for k, v in train_stats.items()},
                     **{f'test_{k}': v for k, v in test_stats.items()},
                     'epoch': epoch,
                     'n_parameters': n_parameters}

        if args.output_dir and utils.is_main_process():
            with (output_dir / "log.txt").open("a") as f:
                f.write(json.dumps(log_stats) + "\n")

            # for evaluation logs
            if coco_evaluator is not None:
                (output_dir / 'eval').mkdir(exist_ok=True)
                if "bbox" in coco_evaluator.coco_eval:
                    filenames = ['latest.pth']
                    if epoch % 50 == 0:
                        filenames.append(f'{epoch:03}.pth')
                    for name in filenames:
                        torch.save(coco_evaluator.coco_eval["bbox"].eval,
                                   output_dir / "eval" / name)

    total_time = time.time() - start_time
    total_time_str = str(datetime.timedelta(seconds=int(total_time)))
    print('Training time {}'.format(total_time_str))


if __name__ == '__main__':
    parser = argparse.ArgumentParser('DETR training and evaluation script', parents=[get_args_parser()])
    args = parser.parse_args()
    if args.output_dir:
        Path(args.output_dir).mkdir(parents=True, exist_ok=True)
    main(args)



File: util/misc.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
Misc functions, including distributed helpers.

Mostly copy-paste from torchvision references.
"""
import os
import subprocess
import time
from collections import defaultdict, deque
import datetime
import pickle
from packaging import version
from typing import Optional, List

import torch
import torch.distributed as dist
from torch import Tensor

# needed due to empty tensor bug in pytorch and torchvision 0.5
import torchvision
if version.parse(torchvision.__version__) < version.parse('0.7'):
    from torchvision.ops import _new_empty_tensor
    from torchvision.ops.misc import _output_size


class SmoothedValue(object):
    """Track a series of values and provide access to smoothed values over a
    window or the global series average.
    """

    def __init__(self, window_size=20, fmt=None):
        if fmt is None:
            fmt = "{median:.4f} ({global_avg:.4f})"
        self.deque = deque(maxlen=window_size)
        self.total = 0.0
        self.count = 0
        self.fmt = fmt

    def update(self, value, n=1):
        self.deque.append(value)
        self.count += n
        self.total += value * n

    def synchronize_between_processes(self):
        """
        Warning: does not synchronize the deque!
        """
        if not is_dist_avail_and_initialized():
            return
        t = torch.tensor([self.count, self.total], dtype=torch.float64, device='cuda')
        dist.barrier()
        dist.all_reduce(t)
        t = t.tolist()
        self.count = int(t[0])
        self.total = t[1]

    @property
    def median(self):
        d = torch.tensor(list(self.deque))
        return d.median().item()

    @property
    def avg(self):
        d = torch.tensor(list(self.deque), dtype=torch.float32)
        return d.mean().item()

    @property
    def global_avg(self):
        return self.total / self.count

    @property
    def max(self):
        return max(self.deque)

    @property
    def value(self):
        return self.deque[-1]

    def __str__(self):
        return self.fmt.format(
            median=self.median,
            avg=self.avg,
            global_avg=self.global_avg,
            max=self.max,
            value=self.value)


def all_gather(data):
    """
    Run all_gather on arbitrary picklable data (not necessarily tensors)
    Args:
        data: any picklable object
    Returns:
        list[data]: list of data gathered from each rank
    """
    world_size = get_world_size()
    if world_size == 1:
        return [data]

    # serialized to a Tensor
    buffer = pickle.dumps(data)
    storage = torch.ByteStorage.from_buffer(buffer)
    tensor = torch.ByteTensor(storage).to("cuda")

    # obtain Tensor size of each rank
    local_size = torch.tensor([tensor.numel()], device="cuda")
    size_list = [torch.tensor([0], device="cuda") for _ in range(world_size)]
    dist.all_gather(size_list, local_size)
    size_list = [int(size.item()) for size in size_list]
    max_size = max(size_list)

    # receiving Tensor from all ranks
    # we pad the tensor because torch all_gather does not support
    # gathering tensors of different shapes
    tensor_list = []
    for _ in size_list:
        tensor_list.append(torch.empty((max_size,), dtype=torch.uint8, device="cuda"))
    if local_size != max_size:
        padding = torch.empty(size=(max_size - local_size,), dtype=torch.uint8, device="cuda")
        tensor = torch.cat((tensor, padding), dim=0)
    dist.all_gather(tensor_list, tensor)

    data_list = []
    for size, tensor in zip(size_list, tensor_list):
        buffer = tensor.cpu().numpy().tobytes()[:size]
        data_list.append(pickle.loads(buffer))

    return data_list


def reduce_dict(input_dict, average=True):
    """
    Args:
        input_dict (dict): all the values will be reduced
        average (bool): whether to do average or sum
    Reduce the values in the dictionary from all processes so that all processes
    have the averaged results. Returns a dict with the same fields as
    input_dict, after reduction.
    """
    world_size = get_world_size()
    if world_size < 2:
        return input_dict
    with torch.no_grad():
        names = []
        values = []
        # sort the keys so that they are consistent across processes
        for k in sorted(input_dict.keys()):
            names.append(k)
            values.append(input_dict[k])
        values = torch.stack(values, dim=0)
        dist.all_reduce(values)
        if average:
            values /= world_size
        reduced_dict = {k: v for k, v in zip(names, values)}
    return reduced_dict


class MetricLogger(object):
    def __init__(self, delimiter="\t"):
        self.meters = defaultdict(SmoothedValue)
        self.delimiter = delimiter

    def update(self, **kwargs):
        for k, v in kwargs.items():
            if isinstance(v, torch.Tensor):
                v = v.item()
            assert isinstance(v, (float, int))
            self.meters[k].update(v)

    def __getattr__(self, attr):
        if attr in self.meters:
            return self.meters[attr]
        if attr in self.__dict__:
            return self.__dict__[attr]
        raise AttributeError("'{}' object has no attribute '{}'".format(
            type(self).__name__, attr))

    def __str__(self):
        loss_str = []
        for name, meter in self.meters.items():
            loss_str.append(
                "{}: {}".format(name, str(meter))
            )
        return self.delimiter.join(loss_str)

    def synchronize_between_processes(self):
        for meter in self.meters.values():
            meter.synchronize_between_processes()

    def add_meter(self, name, meter):
        self.meters[name] = meter

    def log_every(self, iterable, print_freq, header=None):
        i = 0
        if not header:
            header = ''
        start_time = time.time()
        end = time.time()
        iter_time = SmoothedValue(fmt='{avg:.4f}')
        data_time = SmoothedValue(fmt='{avg:.4f}')
        space_fmt = ':' + str(len(str(len(iterable)))) + 'd'
        if torch.cuda.is_available():
            log_msg = self.delimiter.join([
                header,
                '[{0' + space_fmt + '}/{1}]',
                'eta: {eta}',
                '{meters}',
                'time: {time}',
                'data: {data}',
                'max mem: {memory:.0f}'
            ])
        else:
            log_msg = self.delimiter.join([
                header,
                '[{0' + space_fmt + '}/{1}]',
                'eta: {eta}',
                '{meters}',
                'time: {time}',
                'data: {data}'
            ])
        MB = 1024.0 * 1024.0
        for obj in iterable:
            data_time.update(time.time() - end)
            yield obj
            iter_time.update(time.time() - end)
            if i % print_freq == 0 or i == len(iterable) - 1:
                eta_seconds = iter_time.global_avg * (len(iterable) - i)
                eta_string = str(datetime.timedelta(seconds=int(eta_seconds)))
                if torch.cuda.is_available():
                    print(log_msg.format(
                        i, len(iterable), eta=eta_string,
                        meters=str(self),
                        time=str(iter_time), data=str(data_time),
                        memory=torch.cuda.max_memory_allocated() / MB))
                else:
                    print(log_msg.format(
                        i, len(iterable), eta=eta_string,
                        meters=str(self),
                        time=str(iter_time), data=str(data_time)))
            i += 1
            end = time.time()
        total_time = time.time() - start_time
        total_time_str = str(datetime.timedelta(seconds=int(total_time)))
        print('{} Total time: {} ({:.4f} s / it)'.format(
            header, total_time_str, total_time / len(iterable)))


def get_sha():
    cwd = os.path.dirname(os.path.abspath(__file__))

    def _run(command):
        return subprocess.check_output(command, cwd=cwd).decode('ascii').strip()
    sha = 'N/A'
    diff = "clean"
    branch = 'N/A'
    try:
        sha = _run(['git', 'rev-parse', 'HEAD'])
        subprocess.check_output(['git', 'diff'], cwd=cwd)
        diff = _run(['git', 'diff-index', 'HEAD'])
        diff = "has uncommited changes" if diff else "clean"
        branch = _run(['git', 'rev-parse', '--abbrev-ref', 'HEAD'])
    except Exception:
        pass
    message = f"sha: {sha}, status: {diff}, branch: {branch}"
    return message


def collate_fn(batch):
    batch = list(zip(*batch))
    batch[0] = nested_tensor_from_tensor_list(batch[0])
    return tuple(batch)


def _max_by_axis(the_list):
    # type: (List[List[int]]) -> List[int]
    maxes = the_list[0]
    for sublist in the_list[1:]:
        for index, item in enumerate(sublist):
            maxes[index] = max(maxes[index], item)
    return maxes


class NestedTensor(object):
    def __init__(self, tensors, mask: Optional[Tensor]):
        self.tensors = tensors
        self.mask = mask

    def to(self, device):
        # type: (Device) -> NestedTensor # noqa
        cast_tensor = self.tensors.to(device)
        mask = self.mask
        if mask is not None:
            assert mask is not None
            cast_mask = mask.to(device)
        else:
            cast_mask = None
        return NestedTensor(cast_tensor, cast_mask)

    def decompose(self):
        return self.tensors, self.mask

    def __repr__(self):
        return str(self.tensors)


def nested_tensor_from_tensor_list(tensor_list: List[Tensor]):
    # TODO make this more general
    if tensor_list[0].ndim == 3:
        if torchvision._is_tracing():
            # nested_tensor_from_tensor_list() does not export well to ONNX
            # call _onnx_nested_tensor_from_tensor_list() instead
            return _onnx_nested_tensor_from_tensor_list(tensor_list)

        # TODO make it support different-sized images
        max_size = _max_by_axis([list(img.shape) for img in tensor_list])
        # min_size = tuple(min(s) for s in zip(*[img.shape for img in tensor_list]))
        batch_shape = [len(tensor_list)] + max_size
        b, c, h, w = batch_shape
        dtype = tensor_list[0].dtype
        device = tensor_list[0].device
        tensor = torch.zeros(batch_shape, dtype=dtype, device=device)
        mask = torch.ones((b, h, w), dtype=torch.bool, device=device)
        for img, pad_img, m in zip(tensor_list, tensor, mask):
            pad_img[: img.shape[0], : img.shape[1], : img.shape[2]].copy_(img)
            m[: img.shape[1], :img.shape[2]] = False
    else:
        raise ValueError('not supported')
    return NestedTensor(tensor, mask)


# _onnx_nested_tensor_from_tensor_list() is an implementation of
# nested_tensor_from_tensor_list() that is supported by ONNX tracing.
@torch.jit.unused
def _onnx_nested_tensor_from_tensor_list(tensor_list: List[Tensor]) -> NestedTensor:
    max_size = []
    for i in range(tensor_list[0].dim()):
        max_size_i = torch.max(torch.stack([img.shape[i] for img in tensor_list]).to(torch.float32)).to(torch.int64)
        max_size.append(max_size_i)
    max_size = tuple(max_size)

    # work around for
    # pad_img[: img.shape[0], : img.shape[1], : img.shape[2]].copy_(img)
    # m[: img.shape[1], :img.shape[2]] = False
    # which is not yet supported in onnx
    padded_imgs = []
    padded_masks = []
    for img in tensor_list:
        padding = [(s1 - s2) for s1, s2 in zip(max_size, tuple(img.shape))]
        padded_img = torch.nn.functional.pad(img, (0, padding[2], 0, padding[1], 0, padding[0]))
        padded_imgs.append(padded_img)

        m = torch.zeros_like(img[0], dtype=torch.int, device=img.device)
        padded_mask = torch.nn.functional.pad(m, (0, padding[2], 0, padding[1]), "constant", 1)
        padded_masks.append(padded_mask.to(torch.bool))

    tensor = torch.stack(padded_imgs)
    mask = torch.stack(padded_masks)

    return NestedTensor(tensor, mask=mask)


def setup_for_distributed(is_master):
    """
    This function disables printing when not in master process
    """
    import builtins as __builtin__
    builtin_print = __builtin__.print

    def print(*args, **kwargs):
        force = kwargs.pop('force', False)
        if is_master or force:
            builtin_print(*args, **kwargs)

    __builtin__.print = print


def is_dist_avail_and_initialized():
    if not dist.is_available():
        return False
    if not dist.is_initialized():
        return False
    return True


def get_world_size():
    if not is_dist_avail_and_initialized():
        return 1
    return dist.get_world_size()


def get_rank():
    if not is_dist_avail_and_initialized():
        return 0
    return dist.get_rank()


def is_main_process():
    return get_rank() == 0


def save_on_master(*args, **kwargs):
    if is_main_process():
        torch.save(*args, **kwargs)


def init_distributed_mode(args):
    if 'RANK' in os.environ and 'WORLD_SIZE' in os.environ:
        args.rank = int(os.environ["RANK"])
        args.world_size = int(os.environ['WORLD_SIZE'])
        args.gpu = int(os.environ['LOCAL_RANK'])
    elif 'SLURM_PROCID' in os.environ:
        args.rank = int(os.environ['SLURM_PROCID'])
        args.gpu = args.rank % torch.cuda.device_count()
    else:
        print('Not using distributed mode')
        args.distributed = False
        return

    args.distributed = True

    torch.cuda.set_device(args.gpu)
    args.dist_backend = 'nccl'
    print('| distributed init (rank {}): {}'.format(
        args.rank, args.dist_url), flush=True)
    torch.distributed.init_process_group(backend=args.dist_backend, init_method=args.dist_url,
                                         world_size=args.world_size, rank=args.rank)
    torch.distributed.barrier()
    setup_for_distributed(args.rank == 0)


@torch.no_grad()
def accuracy(output, target, topk=(1,)):
    """Computes the precision@k for the specified values of k"""
    if target.numel() == 0:
        return [torch.zeros([], device=output.device)]
    maxk = max(topk)
    batch_size = target.size(0)

    _, pred = output.topk(maxk, 1, True, True)
    pred = pred.t()
    correct = pred.eq(target.view(1, -1).expand_as(pred))

    res = []
    for k in topk:
        correct_k = correct[:k].view(-1).float().sum(0)
        res.append(correct_k.mul_(100.0 / batch_size))
    return res


def interpolate(input, size=None, scale_factor=None, mode="nearest", align_corners=None):
    # type: (Tensor, Optional[List[int]], Optional[float], str, Optional[bool]) -> Tensor
    """
    Equivalent to nn.functional.interpolate, but with support for empty batch sizes.
    This will eventually be supported natively by PyTorch, and this
    class can go away.
    """
    if version.parse(torchvision.__version__) < version.parse('0.7'):
        if input.numel() > 0:
            return torch.nn.functional.interpolate(
                input, size, scale_factor, mode, align_corners
            )

        output_shape = _output_size(2, input, size, scale_factor)
        output_shape = list(input.shape[:-2]) + list(output_shape)
        return _new_empty_tensor(input, output_shape)
    else:
        return torchvision.ops.misc.interpolate(input, size, scale_factor, mode, align_corners)



File: util/box_ops.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
Utilities for bounding box manipulation and GIoU.
"""
import torch
from torchvision.ops.boxes import box_area


def box_cxcywh_to_xyxy(x):
    x_c, y_c, w, h = x.unbind(-1)
    b = [(x_c - 0.5 * w), (y_c - 0.5 * h),
         (x_c + 0.5 * w), (y_c + 0.5 * h)]
    return torch.stack(b, dim=-1)


def box_xyxy_to_cxcywh(x):
    x0, y0, x1, y1 = x.unbind(-1)
    b = [(x0 + x1) / 2, (y0 + y1) / 2,
         (x1 - x0), (y1 - y0)]
    return torch.stack(b, dim=-1)


# modified from torchvision to also return the union
def box_iou(boxes1, boxes2):
    area1 = box_area(boxes1)
    area2 = box_area(boxes2)

    lt = torch.max(boxes1[:, None, :2], boxes2[:, :2])  # [N,M,2]
    rb = torch.min(boxes1[:, None, 2:], boxes2[:, 2:])  # [N,M,2]

    wh = (rb - lt).clamp(min=0)  # [N,M,2]
    inter = wh[:, :, 0] * wh[:, :, 1]  # [N,M]

    union = area1[:, None] + area2 - inter

    iou = inter / union
    return iou, union


def generalized_box_iou(boxes1, boxes2):
    """
    Generalized IoU from https://giou.stanford.edu/

    The boxes should be in [x0, y0, x1, y1] format

    Returns a [N, M] pairwise matrix, where N = len(boxes1)
    and M = len(boxes2)
    """
    # degenerate boxes gives inf / nan results
    # so do an early check
    assert (boxes1[:, 2:] >= boxes1[:, :2]).all()
    assert (boxes2[:, 2:] >= boxes2[:, :2]).all()
    iou, union = box_iou(boxes1, boxes2)

    lt = torch.min(boxes1[:, None, :2], boxes2[:, :2])
    rb = torch.max(boxes1[:, None, 2:], boxes2[:, 2:])

    wh = (rb - lt).clamp(min=0)  # [N,M,2]
    area = wh[:, :, 0] * wh[:, :, 1]

    return iou - (area - union) / area


def masks_to_boxes(masks):
    """Compute the bounding boxes around the provided masks

    The masks should be in format [N, H, W] where N is the number of masks, (H, W) are the spatial dimensions.

    Returns a [N, 4] tensors, with the boxes in xyxy format
    """
    if masks.numel() == 0:
        return torch.zeros((0, 4), device=masks.device)

    h, w = masks.shape[-2:]

    y = torch.arange(0, h, dtype=torch.float)
    x = torch.arange(0, w, dtype=torch.float)
    y, x = torch.meshgrid(y, x)

    x_mask = (masks * x.unsqueeze(0))
    x_max = x_mask.flatten(1).max(-1)[0]
    x_min = x_mask.masked_fill(~(masks.bool()), 1e8).flatten(1).min(-1)[0]

    y_mask = (masks * y.unsqueeze(0))
    y_max = y_mask.flatten(1).max(-1)[0]
    y_min = y_mask.masked_fill(~(masks.bool()), 1e8).flatten(1).min(-1)[0]

    return torch.stack([x_min, y_min, x_max, y_max], 1)



File: util/__init__.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved



File: util/plot_utils.py

"""
Plotting utilities to visualize training logs.
"""
import torch
import pandas as pd
import numpy as np
import seaborn as sns
import matplotlib.pyplot as plt

from pathlib import Path, PurePath


def plot_logs(logs, fields=('class_error', 'loss_bbox_unscaled', 'mAP'), ewm_col=0, log_name='log.txt'):
    '''
    Function to plot specific fields from training log(s). Plots both training and test results.

    :: Inputs - logs = list containing Path objects, each pointing to individual dir with a log file
              - fields = which results to plot from each log file - plots both training and test for each field.
              - ewm_col = optional, which column to use as the exponential weighted smoothing of the plots
              - log_name = optional, name of log file if different than default 'log.txt'.

    :: Outputs - matplotlib plots of results in fields, color coded for each log file.
               - solid lines are training results, dashed lines are test results.

    '''
    func_name = "plot_utils.py::plot_logs"

    # verify logs is a list of Paths (list[Paths]) or single Pathlib object Path,
    # convert single Path to list to avoid 'not iterable' error

    if not isinstance(logs, list):
        if isinstance(logs, PurePath):
            logs = [logs]
            print(f"{func_name} info: logs param expects a list argument, converted to list[Path].")
        else:
            raise ValueError(f"{func_name} - invalid argument for logs parameter.\n \
            Expect list[Path] or single Path obj, received {type(logs)}")

    # Quality checks - verify valid dir(s), that every item in list is Path object, and that log_name exists in each dir
    for i, dir in enumerate(logs):
        if not isinstance(dir, PurePath):
            raise ValueError(f"{func_name} - non-Path object in logs argument of {type(dir)}: \n{dir}")
        if not dir.exists():
            raise ValueError(f"{func_name} - invalid directory in logs argument:\n{dir}")
        # verify log_name exists
        fn = Path(dir / log_name)
        if not fn.exists():
            print(f"-> missing {log_name}.  Have you gotten to Epoch 1 in training?")
            print(f"--> full path of missing log file: {fn}")
            return

    # load log file(s) and plot
    dfs = [pd.read_json(Path(p) / log_name, lines=True) for p in logs]

    fig, axs = plt.subplots(ncols=len(fields), figsize=(16, 5))

    for df, color in zip(dfs, sns.color_palette(n_colors=len(logs))):
        for j, field in enumerate(fields):
            if field == 'mAP':
                coco_eval = pd.DataFrame(
                    np.stack(df.test_coco_eval_bbox.dropna().values)[:, 1]
                ).ewm(com=ewm_col).mean()
                axs[j].plot(coco_eval, c=color)
            else:
                df.interpolate().ewm(com=ewm_col).mean().plot(
                    y=[f'train_{field}', f'test_{field}'],
                    ax=axs[j],
                    color=[color] * 2,
                    style=['-', '--']
                )
    for ax, field in zip(axs, fields):
        ax.legend([Path(p).name for p in logs])
        ax.set_title(field)


def plot_precision_recall(files, naming_scheme='iter'):
    if naming_scheme == 'exp_id':
        # name becomes exp_id
        names = [f.parts[-3] for f in files]
    elif naming_scheme == 'iter':
        names = [f.stem for f in files]
    else:
        raise ValueError(f'not supported {naming_scheme}')
    fig, axs = plt.subplots(ncols=2, figsize=(16, 5))
    for f, color, name in zip(files, sns.color_palette("Blues", n_colors=len(files)), names):
        data = torch.load(f)
        # precision is n_iou, n_points, n_cat, n_area, max_det
        precision = data['precision']
        recall = data['params'].recThrs
        scores = data['scores']
        # take precision for all classes, all areas and 100 detections
        precision = precision[0, :, :, 0, -1].mean(1)
        scores = scores[0, :, :, 0, -1].mean(1)
        prec = precision.mean()
        rec = data['recall'][0, :, 0, -1].mean()
        print(f'{naming_scheme} {name}: mAP@50={prec * 100: 05.1f}, ' +
              f'score={scores.mean():0.3f}, ' +
              f'f1={2 * prec * rec / (prec + rec + 1e-8):0.3f}'
              )
        axs[0].plot(recall, precision, c=color)
        axs[1].plot(recall, scores, c=color)

    axs[0].set_title('Precision / Recall')
    axs[0].legend(names)
    axs[1].set_title('Scores / Recall')
    axs[1].legend(names)
    return fig, axs



File: datasets/coco.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
COCO dataset which returns image_id for evaluation.

Mostly copy-paste from https://github.com/pytorch/vision/blob/13b35ff/references/detection/coco_utils.py
"""
from pathlib import Path

import torch
import torch.utils.data
import torchvision
from pycocotools import mask as coco_mask

import datasets.transforms as T


class CocoDetection(torchvision.datasets.CocoDetection):
    def __init__(self, img_folder, ann_file, transforms, return_masks):
        super(CocoDetection, self).__init__(img_folder, ann_file)
        self._transforms = transforms
        self.prepare = ConvertCocoPolysToMask(return_masks)

    def __getitem__(self, idx):
        img, target = super(CocoDetection, self).__getitem__(idx)
        image_id = self.ids[idx]
        target = {'image_id': image_id, 'annotations': target}
        img, target = self.prepare(img, target)
        if self._transforms is not None:
            img, target = self._transforms(img, target)
        return img, target


def convert_coco_poly_to_mask(segmentations, height, width):
    masks = []
    for polygons in segmentations:
        rles = coco_mask.frPyObjects(polygons, height, width)
        mask = coco_mask.decode(rles)
        if len(mask.shape) < 3:
            mask = mask[..., None]
        mask = torch.as_tensor(mask, dtype=torch.uint8)
        mask = mask.any(dim=2)
        masks.append(mask)
    if masks:
        masks = torch.stack(masks, dim=0)
    else:
        masks = torch.zeros((0, height, width), dtype=torch.uint8)
    return masks


class ConvertCocoPolysToMask(object):
    def __init__(self, return_masks=False):
        self.return_masks = return_masks

    def __call__(self, image, target):
        w, h = image.size

        image_id = target["image_id"]
        image_id = torch.tensor([image_id])

        anno = target["annotations"]

        anno = [obj for obj in anno if 'iscrowd' not in obj or obj['iscrowd'] == 0]

        boxes = [obj["bbox"] for obj in anno]
        # guard against no boxes via resizing
        boxes = torch.as_tensor(boxes, dtype=torch.float32).reshape(-1, 4)
        boxes[:, 2:] += boxes[:, :2]
        boxes[:, 0::2].clamp_(min=0, max=w)
        boxes[:, 1::2].clamp_(min=0, max=h)

        classes = [obj["category_id"] for obj in anno]
        classes = torch.tensor(classes, dtype=torch.int64)

        if self.return_masks:
            segmentations = [obj["segmentation"] for obj in anno]
            masks = convert_coco_poly_to_mask(segmentations, h, w)

        keypoints = None
        if anno and "keypoints" in anno[0]:
            keypoints = [obj["keypoints"] for obj in anno]
            keypoints = torch.as_tensor(keypoints, dtype=torch.float32)
            num_keypoints = keypoints.shape[0]
            if num_keypoints:
                keypoints = keypoints.view(num_keypoints, -1, 3)

        keep = (boxes[:, 3] > boxes[:, 1]) & (boxes[:, 2] > boxes[:, 0])
        boxes = boxes[keep]
        classes = classes[keep]
        if self.return_masks:
            masks = masks[keep]
        if keypoints is not None:
            keypoints = keypoints[keep]

        target = {}
        target["boxes"] = boxes
        target["labels"] = classes
        if self.return_masks:
            target["masks"] = masks
        target["image_id"] = image_id
        if keypoints is not None:
            target["keypoints"] = keypoints

        # for conversion to coco api
        area = torch.tensor([obj["area"] for obj in anno])
        iscrowd = torch.tensor([obj["iscrowd"] if "iscrowd" in obj else 0 for obj in anno])
        target["area"] = area[keep]
        target["iscrowd"] = iscrowd[keep]

        target["orig_size"] = torch.as_tensor([int(h), int(w)])
        target["size"] = torch.as_tensor([int(h), int(w)])

        return image, target


def make_coco_transforms(image_set):

    normalize = T.Compose([
        T.ToTensor(),
        T.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
    ])

    scales = [480, 512, 544, 576, 608, 640, 672, 704, 736, 768, 800]

    if image_set == 'train':
        return T.Compose([
            T.RandomHorizontalFlip(),
            T.RandomSelect(
                T.RandomResize(scales, max_size=1333),
                T.Compose([
                    T.RandomResize([400, 500, 600]),
                    T.RandomSizeCrop(384, 600),
                    T.RandomResize(scales, max_size=1333),
                ])
            ),
            normalize,
        ])

    if image_set == 'val':
        return T.Compose([
            T.RandomResize([800], max_size=1333),
            normalize,
        ])

    raise ValueError(f'unknown {image_set}')


def build(image_set, args):
    root = Path(args.coco_path)
    assert root.exists(), f'provided COCO path {root} does not exist'
    mode = 'instances'
    PATHS = {
        "train": (root / "train2017", root / "annotations" / f'{mode}_train2017.json'),
        "val": (root / "val2017", root / "annotations" / f'{mode}_val2017.json'),
    }

    img_folder, ann_file = PATHS[image_set]
    dataset = CocoDetection(img_folder, ann_file, transforms=make_coco_transforms(image_set), return_masks=args.masks)
    return dataset



File: datasets/transforms.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
Transforms and data augmentation for both image + bbox.
"""
import random

import PIL
import torch
import torchvision.transforms as T
import torchvision.transforms.functional as F

from util.box_ops import box_xyxy_to_cxcywh
from util.misc import interpolate


def crop(image, target, region):
    cropped_image = F.crop(image, *region)

    target = target.copy()
    i, j, h, w = region

    # should we do something wrt the original size?
    target["size"] = torch.tensor([h, w])

    fields = ["labels", "area", "iscrowd"]

    if "boxes" in target:
        boxes = target["boxes"]
        max_size = torch.as_tensor([w, h], dtype=torch.float32)
        cropped_boxes = boxes - torch.as_tensor([j, i, j, i])
        cropped_boxes = torch.min(cropped_boxes.reshape(-1, 2, 2), max_size)
        cropped_boxes = cropped_boxes.clamp(min=0)
        area = (cropped_boxes[:, 1, :] - cropped_boxes[:, 0, :]).prod(dim=1)
        target["boxes"] = cropped_boxes.reshape(-1, 4)
        target["area"] = area
        fields.append("boxes")

    if "masks" in target:
        # FIXME should we update the area here if there are no boxes?
        target['masks'] = target['masks'][:, i:i + h, j:j + w]
        fields.append("masks")

    # remove elements for which the boxes or masks that have zero area
    if "boxes" in target or "masks" in target:
        # favor boxes selection when defining which elements to keep
        # this is compatible with previous implementation
        if "boxes" in target:
            cropped_boxes = target['boxes'].reshape(-1, 2, 2)
            keep = torch.all(cropped_boxes[:, 1, :] > cropped_boxes[:, 0, :], dim=1)
        else:
            keep = target['masks'].flatten(1).any(1)

        for field in fields:
            target[field] = target[field][keep]

    return cropped_image, target


def hflip(image, target):
    flipped_image = F.hflip(image)

    w, h = image.size

    target = target.copy()
    if "boxes" in target:
        boxes = target["boxes"]
        boxes = boxes[:, [2, 1, 0, 3]] * torch.as_tensor([-1, 1, -1, 1]) + torch.as_tensor([w, 0, w, 0])
        target["boxes"] = boxes

    if "masks" in target:
        target['masks'] = target['masks'].flip(-1)

    return flipped_image, target


def resize(image, target, size, max_size=None):
    # size can be min_size (scalar) or (w, h) tuple

    def get_size_with_aspect_ratio(image_size, size, max_size=None):
        w, h = image_size
        if max_size is not None:
            min_original_size = float(min((w, h)))
            max_original_size = float(max((w, h)))
            if max_original_size / min_original_size * size > max_size:
                size = int(round(max_size * min_original_size / max_original_size))

        if (w <= h and w == size) or (h <= w and h == size):
            return (h, w)

        if w < h:
            ow = size
            oh = int(size * h / w)
        else:
            oh = size
            ow = int(size * w / h)

        return (oh, ow)

    def get_size(image_size, size, max_size=None):
        if isinstance(size, (list, tuple)):
            return size[::-1]
        else:
            return get_size_with_aspect_ratio(image_size, size, max_size)

    size = get_size(image.size, size, max_size)
    rescaled_image = F.resize(image, size)

    if target is None:
        return rescaled_image, None

    ratios = tuple(float(s) / float(s_orig) for s, s_orig in zip(rescaled_image.size, image.size))
    ratio_width, ratio_height = ratios

    target = target.copy()
    if "boxes" in target:
        boxes = target["boxes"]
        scaled_boxes = boxes * torch.as_tensor([ratio_width, ratio_height, ratio_width, ratio_height])
        target["boxes"] = scaled_boxes

    if "area" in target:
        area = target["area"]
        scaled_area = area * (ratio_width * ratio_height)
        target["area"] = scaled_area

    h, w = size
    target["size"] = torch.tensor([h, w])

    if "masks" in target:
        target['masks'] = interpolate(
            target['masks'][:, None].float(), size, mode="nearest")[:, 0] > 0.5

    return rescaled_image, target


def pad(image, target, padding):
    # assumes that we only pad on the bottom right corners
    padded_image = F.pad(image, (0, 0, padding[0], padding[1]))
    if target is None:
        return padded_image, None
    target = target.copy()
    # should we do something wrt the original size?
    target["size"] = torch.tensor(padded_image.size[::-1])
    if "masks" in target:
        target['masks'] = torch.nn.functional.pad(target['masks'], (0, padding[0], 0, padding[1]))
    return padded_image, target


class RandomCrop(object):
    def __init__(self, size):
        self.size = size

    def __call__(self, img, target):
        region = T.RandomCrop.get_params(img, self.size)
        return crop(img, target, region)


class RandomSizeCrop(object):
    def __init__(self, min_size: int, max_size: int):
        self.min_size = min_size
        self.max_size = max_size

    def __call__(self, img: PIL.Image.Image, target: dict):
        w = random.randint(self.min_size, min(img.width, self.max_size))
        h = random.randint(self.min_size, min(img.height, self.max_size))
        region = T.RandomCrop.get_params(img, [h, w])
        return crop(img, target, region)


class CenterCrop(object):
    def __init__(self, size):
        self.size = size

    def __call__(self, img, target):
        image_width, image_height = img.size
        crop_height, crop_width = self.size
        crop_top = int(round((image_height - crop_height) / 2.))
        crop_left = int(round((image_width - crop_width) / 2.))
        return crop(img, target, (crop_top, crop_left, crop_height, crop_width))


class RandomHorizontalFlip(object):
    def __init__(self, p=0.5):
        self.p = p

    def __call__(self, img, target):
        if random.random() < self.p:
            return hflip(img, target)
        return img, target


class RandomResize(object):
    def __init__(self, sizes, max_size=None):
        assert isinstance(sizes, (list, tuple))
        self.sizes = sizes
        self.max_size = max_size

    def __call__(self, img, target=None):
        size = random.choice(self.sizes)
        return resize(img, target, size, self.max_size)


class RandomPad(object):
    def __init__(self, max_pad):
        self.max_pad = max_pad

    def __call__(self, img, target):
        pad_x = random.randint(0, self.max_pad)
        pad_y = random.randint(0, self.max_pad)
        return pad(img, target, (pad_x, pad_y))


class RandomSelect(object):
    """
    Randomly selects between transforms1 and transforms2,
    with probability p for transforms1 and (1 - p) for transforms2
    """
    def __init__(self, transforms1, transforms2, p=0.5):
        self.transforms1 = transforms1
        self.transforms2 = transforms2
        self.p = p

    def __call__(self, img, target):
        if random.random() < self.p:
            return self.transforms1(img, target)
        return self.transforms2(img, target)


class ToTensor(object):
    def __call__(self, img, target):
        return F.to_tensor(img), target


class RandomErasing(object):

    def __init__(self, *args, **kwargs):
        self.eraser = T.RandomErasing(*args, **kwargs)

    def __call__(self, img, target):
        return self.eraser(img), target


class Normalize(object):
    def __init__(self, mean, std):
        self.mean = mean
        self.std = std

    def __call__(self, image, target=None):
        image = F.normalize(image, mean=self.mean, std=self.std)
        if target is None:
            return image, None
        target = target.copy()
        h, w = image.shape[-2:]
        if "boxes" in target:
            boxes = target["boxes"]
            boxes = box_xyxy_to_cxcywh(boxes)
            boxes = boxes / torch.tensor([w, h, w, h], dtype=torch.float32)
            target["boxes"] = boxes
        return image, target


class Compose(object):
    def __init__(self, transforms):
        self.transforms = transforms

    def __call__(self, image, target):
        for t in self.transforms:
            image, target = t(image, target)
        return image, target

    def __repr__(self):
        format_string = self.__class__.__name__ + "("
        for t in self.transforms:
            format_string += "\n"
            format_string += "    {0}".format(t)
        format_string += "\n)"
        return format_string



File: datasets/panoptic_eval.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
import json
import os

import util.misc as utils

try:
    from panopticapi.evaluation import pq_compute
except ImportError:
    pass


class PanopticEvaluator(object):
    def __init__(self, ann_file, ann_folder, output_dir="panoptic_eval"):
        self.gt_json = ann_file
        self.gt_folder = ann_folder
        if utils.is_main_process():
            if not os.path.exists(output_dir):
                os.mkdir(output_dir)
        self.output_dir = output_dir
        self.predictions = []

    def update(self, predictions):
        for p in predictions:
            with open(os.path.join(self.output_dir, p["file_name"]), "wb") as f:
                f.write(p.pop("png_string"))

        self.predictions += predictions

    def synchronize_between_processes(self):
        all_predictions = utils.all_gather(self.predictions)
        merged_predictions = []
        for p in all_predictions:
            merged_predictions += p
        self.predictions = merged_predictions

    def summarize(self):
        if utils.is_main_process():
            json_data = {"annotations": self.predictions}
            predictions_json = os.path.join(self.output_dir, "predictions.json")
            with open(predictions_json, "w") as f:
                f.write(json.dumps(json_data))
            return pq_compute(self.gt_json, predictions_json, gt_folder=self.gt_folder, pred_folder=self.output_dir)
        return None



File: datasets/__init__.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
import torch.utils.data
import torchvision

from .coco import build as build_coco


def get_coco_api_from_dataset(dataset):
    for _ in range(10):
        # if isinstance(dataset, torchvision.datasets.CocoDetection):
        #     break
        if isinstance(dataset, torch.utils.data.Subset):
            dataset = dataset.dataset
    if isinstance(dataset, torchvision.datasets.CocoDetection):
        return dataset.coco


def build_dataset(image_set, args):
    if args.dataset_file == 'coco':
        return build_coco(image_set, args)
    if args.dataset_file == 'coco_panoptic':
        # to avoid making panopticapi required for coco
        from .coco_panoptic import build as build_coco_panoptic
        return build_coco_panoptic(image_set, args)
    raise ValueError(f'dataset {args.dataset_file} not supported')



File: datasets/coco_eval.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
COCO evaluator that works in distributed mode.

Mostly copy-paste from https://github.com/pytorch/vision/blob/edfd5a7/references/detection/coco_eval.py
The difference is that there is less copy-pasting from pycocotools
in the end of the file, as python3 can suppress prints with contextlib
"""
import os
import contextlib
import copy
import numpy as np
import torch

from pycocotools.cocoeval import COCOeval
from pycocotools.coco import COCO
import pycocotools.mask as mask_util

from util.misc import all_gather


class CocoEvaluator(object):
    def __init__(self, coco_gt, iou_types):
        assert isinstance(iou_types, (list, tuple))
        coco_gt = copy.deepcopy(coco_gt)
        self.coco_gt = coco_gt

        self.iou_types = iou_types
        self.coco_eval = {}
        for iou_type in iou_types:
            self.coco_eval[iou_type] = COCOeval(coco_gt, iouType=iou_type)

        self.img_ids = []
        self.eval_imgs = {k: [] for k in iou_types}

    def update(self, predictions):
        img_ids = list(np.unique(list(predictions.keys())))
        self.img_ids.extend(img_ids)

        for iou_type in self.iou_types:
            results = self.prepare(predictions, iou_type)

            # suppress pycocotools prints
            with open(os.devnull, 'w') as devnull:
                with contextlib.redirect_stdout(devnull):
                    coco_dt = COCO.loadRes(self.coco_gt, results) if results else COCO()
            coco_eval = self.coco_eval[iou_type]

            coco_eval.cocoDt = coco_dt
            coco_eval.params.imgIds = list(img_ids)
            img_ids, eval_imgs = evaluate(coco_eval)

            self.eval_imgs[iou_type].append(eval_imgs)

    def synchronize_between_processes(self):
        for iou_type in self.iou_types:
            self.eval_imgs[iou_type] = np.concatenate(self.eval_imgs[iou_type], 2)
            create_common_coco_eval(self.coco_eval[iou_type], self.img_ids, self.eval_imgs[iou_type])

    def accumulate(self):
        for coco_eval in self.coco_eval.values():
            coco_eval.accumulate()

    def summarize(self):
        for iou_type, coco_eval in self.coco_eval.items():
            print("IoU metric: {}".format(iou_type))
            coco_eval.summarize()

    def prepare(self, predictions, iou_type):
        if iou_type == "bbox":
            return self.prepare_for_coco_detection(predictions)
        elif iou_type == "segm":
            return self.prepare_for_coco_segmentation(predictions)
        elif iou_type == "keypoints":
            return self.prepare_for_coco_keypoint(predictions)
        else:
            raise ValueError("Unknown iou type {}".format(iou_type))

    def prepare_for_coco_detection(self, predictions):
        coco_results = []
        for original_id, prediction in predictions.items():
            if len(prediction) == 0:
                continue

            boxes = prediction["boxes"]
            boxes = convert_to_xywh(boxes).tolist()
            scores = prediction["scores"].tolist()
            labels = prediction["labels"].tolist()

            coco_results.extend(
                [
                    {
                        "image_id": original_id,
                        "category_id": labels[k],
                        "bbox": box,
                        "score": scores[k],
                    }
                    for k, box in enumerate(boxes)
                ]
            )
        return coco_results

    def prepare_for_coco_segmentation(self, predictions):
        coco_results = []
        for original_id, prediction in predictions.items():
            if len(prediction) == 0:
                continue

            scores = prediction["scores"]
            labels = prediction["labels"]
            masks = prediction["masks"]

            masks = masks > 0.5

            scores = prediction["scores"].tolist()
            labels = prediction["labels"].tolist()

            rles = [
                mask_util.encode(np.array(mask[0, :, :, np.newaxis], dtype=np.uint8, order="F"))[0]
                for mask in masks
            ]
            for rle in rles:
                rle["counts"] = rle["counts"].decode("utf-8")

            coco_results.extend(
                [
                    {
                        "image_id": original_id,
                        "category_id": labels[k],
                        "segmentation": rle,
                        "score": scores[k],
                    }
                    for k, rle in enumerate(rles)
                ]
            )
        return coco_results

    def prepare_for_coco_keypoint(self, predictions):
        coco_results = []
        for original_id, prediction in predictions.items():
            if len(prediction) == 0:
                continue

            boxes = prediction["boxes"]
            boxes = convert_to_xywh(boxes).tolist()
            scores = prediction["scores"].tolist()
            labels = prediction["labels"].tolist()
            keypoints = prediction["keypoints"]
            keypoints = keypoints.flatten(start_dim=1).tolist()

            coco_results.extend(
                [
                    {
                        "image_id": original_id,
                        "category_id": labels[k],
                        'keypoints': keypoint,
                        "score": scores[k],
                    }
                    for k, keypoint in enumerate(keypoints)
                ]
            )
        return coco_results


def convert_to_xywh(boxes):
    xmin, ymin, xmax, ymax = boxes.unbind(1)
    return torch.stack((xmin, ymin, xmax - xmin, ymax - ymin), dim=1)


def merge(img_ids, eval_imgs):
    all_img_ids = all_gather(img_ids)
    all_eval_imgs = all_gather(eval_imgs)

    merged_img_ids = []
    for p in all_img_ids:
        merged_img_ids.extend(p)

    merged_eval_imgs = []
    for p in all_eval_imgs:
        merged_eval_imgs.append(p)

    merged_img_ids = np.array(merged_img_ids)
    merged_eval_imgs = np.concatenate(merged_eval_imgs, 2)

    # keep only unique (and in sorted order) images
    merged_img_ids, idx = np.unique(merged_img_ids, return_index=True)
    merged_eval_imgs = merged_eval_imgs[..., idx]

    return merged_img_ids, merged_eval_imgs


def create_common_coco_eval(coco_eval, img_ids, eval_imgs):
    img_ids, eval_imgs = merge(img_ids, eval_imgs)
    img_ids = list(img_ids)
    eval_imgs = list(eval_imgs.flatten())

    coco_eval.evalImgs = eval_imgs
    coco_eval.params.imgIds = img_ids
    coco_eval._paramsEval = copy.deepcopy(coco_eval.params)


#################################################################
# From pycocotools, just removed the prints and fixed
# a Python3 bug about unicode not defined
#################################################################


def evaluate(self):
    '''
    Run per image evaluation on given images and store results (a list of dict) in self.evalImgs
    :return: None
    '''
    # tic = time.time()
    # print('Running per image evaluation...')
    p = self.params
    # add backward compatibility if useSegm is specified in params
    if p.useSegm is not None:
        p.iouType = 'segm' if p.useSegm == 1 else 'bbox'
        print('useSegm (deprecated) is not None. Running {} evaluation'.format(p.iouType))
    # print('Evaluate annotation type *{}*'.format(p.iouType))
    p.imgIds = list(np.unique(p.imgIds))
    if p.useCats:
        p.catIds = list(np.unique(p.catIds))
    p.maxDets = sorted(p.maxDets)
    self.params = p

    self._prepare()
    # loop through images, area range, max detection number
    catIds = p.catIds if p.useCats else [-1]

    if p.iouType == 'segm' or p.iouType == 'bbox':
        computeIoU = self.computeIoU
    elif p.iouType == 'keypoints':
        computeIoU = self.computeOks
    self.ious = {
        (imgId, catId): computeIoU(imgId, catId)
        for imgId in p.imgIds
        for catId in catIds}

    evaluateImg = self.evaluateImg
    maxDet = p.maxDets[-1]
    evalImgs = [
        evaluateImg(imgId, catId, areaRng, maxDet)
        for catId in catIds
        for areaRng in p.areaRng
        for imgId in p.imgIds
    ]
    # this is NOT in the pycocotools code, but could be done outside
    evalImgs = np.asarray(evalImgs).reshape(len(catIds), len(p.areaRng), len(p.imgIds))
    self._paramsEval = copy.deepcopy(self.params)
    # toc = time.time()
    # print('DONE (t={:0.2f}s).'.format(toc-tic))
    return p.imgIds, evalImgs

#################################################################
# end of straight copy from pycocotools, just removing the prints
#################################################################



File: datasets/coco_panoptic.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
import json
from pathlib import Path

import numpy as np
import torch
from PIL import Image

from panopticapi.utils import rgb2id
from util.box_ops import masks_to_boxes

from .coco import make_coco_transforms


class CocoPanoptic:
    def __init__(self, img_folder, ann_folder, ann_file, transforms=None, return_masks=True):
        with open(ann_file, 'r') as f:
            self.coco = json.load(f)

        # sort 'images' field so that they are aligned with 'annotations'
        # i.e., in alphabetical order
        self.coco['images'] = sorted(self.coco['images'], key=lambda x: x['id'])
        # sanity check
        if "annotations" in self.coco:
            for img, ann in zip(self.coco['images'], self.coco['annotations']):
                assert img['file_name'][:-4] == ann['file_name'][:-4]

        self.img_folder = img_folder
        self.ann_folder = ann_folder
        self.ann_file = ann_file
        self.transforms = transforms
        self.return_masks = return_masks

    def __getitem__(self, idx):
        ann_info = self.coco['annotations'][idx] if "annotations" in self.coco else self.coco['images'][idx]
        img_path = Path(self.img_folder) / ann_info['file_name'].replace('.png', '.jpg')
        ann_path = Path(self.ann_folder) / ann_info['file_name']

        img = Image.open(img_path).convert('RGB')
        w, h = img.size
        if "segments_info" in ann_info:
            masks = np.asarray(Image.open(ann_path), dtype=np.uint32)
            masks = rgb2id(masks)

            ids = np.array([ann['id'] for ann in ann_info['segments_info']])
            masks = masks == ids[:, None, None]

            masks = torch.as_tensor(masks, dtype=torch.uint8)
            labels = torch.tensor([ann['category_id'] for ann in ann_info['segments_info']], dtype=torch.int64)

        target = {}
        target['image_id'] = torch.tensor([ann_info['image_id'] if "image_id" in ann_info else ann_info["id"]])
        if self.return_masks:
            target['masks'] = masks
        target['labels'] = labels

        target["boxes"] = masks_to_boxes(masks)

        target['size'] = torch.as_tensor([int(h), int(w)])
        target['orig_size'] = torch.as_tensor([int(h), int(w)])
        if "segments_info" in ann_info:
            for name in ['iscrowd', 'area']:
                target[name] = torch.tensor([ann[name] for ann in ann_info['segments_info']])

        if self.transforms is not None:
            img, target = self.transforms(img, target)

        return img, target

    def __len__(self):
        return len(self.coco['images'])

    def get_height_and_width(self, idx):
        img_info = self.coco['images'][idx]
        height = img_info['height']
        width = img_info['width']
        return height, width


def build(image_set, args):
    img_folder_root = Path(args.coco_path)
    ann_folder_root = Path(args.coco_panoptic_path)
    assert img_folder_root.exists(), f'provided COCO path {img_folder_root} does not exist'
    assert ann_folder_root.exists(), f'provided COCO path {ann_folder_root} does not exist'
    mode = 'panoptic'
    PATHS = {
        "train": ("train2017", Path("annotations") / f'{mode}_train2017.json'),
        "val": ("val2017", Path("annotations") / f'{mode}_val2017.json'),
    }

    img_folder, ann_file = PATHS[image_set]
    img_folder_path = img_folder_root / img_folder
    ann_folder = ann_folder_root / f'{mode}_{img_folder}'
    ann_file = ann_folder_root / ann_file

    dataset = CocoPanoptic(img_folder_path, ann_folder, ann_file,
                           transforms=make_coco_transforms(image_set), return_masks=args.masks)

    return dataset



File: models/detr.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
DETR model and criterion classes.
"""
import torch
import torch.nn.functional as F
from torch import nn

from util import box_ops
from util.misc import (NestedTensor, nested_tensor_from_tensor_list,
                       accuracy, get_world_size, interpolate,
                       is_dist_avail_and_initialized)

from .backbone import build_backbone
from .matcher import build_matcher
from .segmentation import (DETRsegm, PostProcessPanoptic, PostProcessSegm,
                           dice_loss, sigmoid_focal_loss)
from .transformer import build_transformer


class DETR(nn.Module):
    """ This is the DETR module that performs object detection """
    def __init__(self, backbone, transformer, num_classes, num_queries, aux_loss=False):
        """ Initializes the model.
        Parameters:
            backbone: torch module of the backbone to be used. See backbone.py
            transformer: torch module of the transformer architecture. See transformer.py
            num_classes: number of object classes
            num_queries: number of object queries, ie detection slot. This is the maximal number of objects
                         DETR can detect in a single image. For COCO, we recommend 100 queries.
            aux_loss: True if auxiliary decoding losses (loss at each decoder layer) are to be used.
        """
        super().__init__()
        self.num_queries = num_queries
        self.transformer = transformer
        hidden_dim = transformer.d_model
        self.class_embed = nn.Linear(hidden_dim, num_classes + 1)
        self.bbox_embed = MLP(hidden_dim, hidden_dim, 4, 3)
        self.query_embed = nn.Embedding(num_queries, hidden_dim)
        self.input_proj = nn.Conv2d(backbone.num_channels, hidden_dim, kernel_size=1)
        self.backbone = backbone
        self.aux_loss = aux_loss

    def forward(self, samples: NestedTensor):
        """ The forward expects a NestedTensor, which consists of:
               - samples.tensor: batched images, of shape [batch_size x 3 x H x W]
               - samples.mask: a binary mask of shape [batch_size x H x W], containing 1 on padded pixels

            It returns a dict with the following elements:
               - "pred_logits": the classification logits (including no-object) for all queries.
                                Shape= [batch_size x num_queries x (num_classes + 1)]
               - "pred_boxes": The normalized boxes coordinates for all queries, represented as
                               (center_x, center_y, height, width). These values are normalized in [0, 1],
                               relative to the size of each individual image (disregarding possible padding).
                               See PostProcess for information on how to retrieve the unnormalized bounding box.
               - "aux_outputs": Optional, only returned when auxilary losses are activated. It is a list of
                                dictionnaries containing the two above keys for each decoder layer.
        """
        if isinstance(samples, (list, torch.Tensor)):
            samples = nested_tensor_from_tensor_list(samples)
        features, pos = self.backbone(samples)

        src, mask = features[-1].decompose()
        assert mask is not None
        hs = self.transformer(self.input_proj(src), mask, self.query_embed.weight, pos[-1])[0]

        outputs_class = self.class_embed(hs)
        outputs_coord = self.bbox_embed(hs).sigmoid()
        out = {'pred_logits': outputs_class[-1], 'pred_boxes': outputs_coord[-1]}
        if self.aux_loss:
            out['aux_outputs'] = self._set_aux_loss(outputs_class, outputs_coord)
        return out

    @torch.jit.unused
    def _set_aux_loss(self, outputs_class, outputs_coord):
        # this is a workaround to make torchscript happy, as torchscript
        # doesn't support dictionary with non-homogeneous values, such
        # as a dict having both a Tensor and a list.
        return [{'pred_logits': a, 'pred_boxes': b}
                for a, b in zip(outputs_class[:-1], outputs_coord[:-1])]


class SetCriterion(nn.Module):
    """ This class computes the loss for DETR.
    The process happens in two steps:
        1) we compute hungarian assignment between ground truth boxes and the outputs of the model
        2) we supervise each pair of matched ground-truth / prediction (supervise class and box)
    """
    def __init__(self, num_classes, matcher, weight_dict, eos_coef, losses):
        """ Create the criterion.
        Parameters:
            num_classes: number of object categories, omitting the special no-object category
            matcher: module able to compute a matching between targets and proposals
            weight_dict: dict containing as key the names of the losses and as values their relative weight.
            eos_coef: relative classification weight applied to the no-object category
            losses: list of all the losses to be applied. See get_loss for list of available losses.
        """
        super().__init__()
        self.num_classes = num_classes
        self.matcher = matcher
        self.weight_dict = weight_dict
        self.eos_coef = eos_coef
        self.losses = losses
        empty_weight = torch.ones(self.num_classes + 1)
        empty_weight[-1] = self.eos_coef
        self.register_buffer('empty_weight', empty_weight)

    def loss_labels(self, outputs, targets, indices, num_boxes, log=True):
        """Classification loss (NLL)
        targets dicts must contain the key "labels" containing a tensor of dim [nb_target_boxes]
        """
        assert 'pred_logits' in outputs
        src_logits = outputs['pred_logits']

        idx = self._get_src_permutation_idx(indices)
        target_classes_o = torch.cat([t["labels"][J] for t, (_, J) in zip(targets, indices)])
        target_classes = torch.full(src_logits.shape[:2], self.num_classes,
                                    dtype=torch.int64, device=src_logits.device)
        target_classes[idx] = target_classes_o

        loss_ce = F.cross_entropy(src_logits.transpose(1, 2), target_classes, self.empty_weight)
        losses = {'loss_ce': loss_ce}

        if log:
            # TODO this should probably be a separate loss, not hacked in this one here
            losses['class_error'] = 100 - accuracy(src_logits[idx], target_classes_o)[0]
        return losses

    @torch.no_grad()
    def loss_cardinality(self, outputs, targets, indices, num_boxes):
        """ Compute the cardinality error, ie the absolute error in the number of predicted non-empty boxes
        This is not really a loss, it is intended for logging purposes only. It doesn't propagate gradients
        """
        pred_logits = outputs['pred_logits']
        device = pred_logits.device
        tgt_lengths = torch.as_tensor([len(v["labels"]) for v in targets], device=device)
        # Count the number of predictions that are NOT "no-object" (which is the last class)
        card_pred = (pred_logits.argmax(-1) != pred_logits.shape[-1] - 1).sum(1)
        card_err = F.l1_loss(card_pred.float(), tgt_lengths.float())
        losses = {'cardinality_error': card_err}
        return losses

    def loss_boxes(self, outputs, targets, indices, num_boxes):
        """Compute the losses related to the bounding boxes, the L1 regression loss and the GIoU loss
           targets dicts must contain the key "boxes" containing a tensor of dim [nb_target_boxes, 4]
           The target boxes are expected in format (center_x, center_y, w, h), normalized by the image size.
        """
        assert 'pred_boxes' in outputs
        idx = self._get_src_permutation_idx(indices)
        src_boxes = outputs['pred_boxes'][idx]
        target_boxes = torch.cat([t['boxes'][i] for t, (_, i) in zip(targets, indices)], dim=0)

        loss_bbox = F.l1_loss(src_boxes, target_boxes, reduction='none')

        losses = {}
        losses['loss_bbox'] = loss_bbox.sum() / num_boxes

        loss_giou = 1 - torch.diag(box_ops.generalized_box_iou(
            box_ops.box_cxcywh_to_xyxy(src_boxes),
            box_ops.box_cxcywh_to_xyxy(target_boxes)))
        losses['loss_giou'] = loss_giou.sum() / num_boxes
        return losses

    def loss_masks(self, outputs, targets, indices, num_boxes):
        """Compute the losses related to the masks: the focal loss and the dice loss.
           targets dicts must contain the key "masks" containing a tensor of dim [nb_target_boxes, h, w]
        """
        assert "pred_masks" in outputs

        src_idx = self._get_src_permutation_idx(indices)
        tgt_idx = self._get_tgt_permutation_idx(indices)
        src_masks = outputs["pred_masks"]
        src_masks = src_masks[src_idx]
        masks = [t["masks"] for t in targets]
        # TODO use valid to mask invalid areas due to padding in loss
        target_masks, valid = nested_tensor_from_tensor_list(masks).decompose()
        target_masks = target_masks.to(src_masks)
        target_masks = target_masks[tgt_idx]

        # upsample predictions to the target size
        src_masks = interpolate(src_masks[:, None], size=target_masks.shape[-2:],
                                mode="bilinear", align_corners=False)
        src_masks = src_masks[:, 0].flatten(1)

        target_masks = target_masks.flatten(1)
        target_masks = target_masks.view(src_masks.shape)
        losses = {
            "loss_mask": sigmoid_focal_loss(src_masks, target_masks, num_boxes),
            "loss_dice": dice_loss(src_masks, target_masks, num_boxes),
        }
        return losses

    def _get_src_permutation_idx(self, indices):
        # permute predictions following indices
        batch_idx = torch.cat([torch.full_like(src, i) for i, (src, _) in enumerate(indices)])
        src_idx = torch.cat([src for (src, _) in indices])
        return batch_idx, src_idx

    def _get_tgt_permutation_idx(self, indices):
        # permute targets following indices
        batch_idx = torch.cat([torch.full_like(tgt, i) for i, (_, tgt) in enumerate(indices)])
        tgt_idx = torch.cat([tgt for (_, tgt) in indices])
        return batch_idx, tgt_idx

    def get_loss(self, loss, outputs, targets, indices, num_boxes, **kwargs):
        loss_map = {
            'labels': self.loss_labels,
            'cardinality': self.loss_cardinality,
            'boxes': self.loss_boxes,
            'masks': self.loss_masks
        }
        assert loss in loss_map, f'do you really want to compute {loss} loss?'
        return loss_map[loss](outputs, targets, indices, num_boxes, **kwargs)

    def forward(self, outputs, targets):
        """ This performs the loss computation.
        Parameters:
             outputs: dict of tensors, see the output specification of the model for the format
             targets: list of dicts, such that len(targets) == batch_size.
                      The expected keys in each dict depends on the losses applied, see each loss' doc
        """
        outputs_without_aux = {k: v for k, v in outputs.items() if k != 'aux_outputs'}

        # Retrieve the matching between the outputs of the last layer and the targets
        indices = self.matcher(outputs_without_aux, targets)

        # Compute the average number of target boxes accross all nodes, for normalization purposes
        num_boxes = sum(len(t["labels"]) for t in targets)
        num_boxes = torch.as_tensor([num_boxes], dtype=torch.float, device=next(iter(outputs.values())).device)
        if is_dist_avail_and_initialized():
            torch.distributed.all_reduce(num_boxes)
        num_boxes = torch.clamp(num_boxes / get_world_size(), min=1).item()

        # Compute all the requested losses
        losses = {}
        for loss in self.losses:
            losses.update(self.get_loss(loss, outputs, targets, indices, num_boxes))

        # In case of auxiliary losses, we repeat this process with the output of each intermediate layer.
        if 'aux_outputs' in outputs:
            for i, aux_outputs in enumerate(outputs['aux_outputs']):
                indices = self.matcher(aux_outputs, targets)
                for loss in self.losses:
                    if loss == 'masks':
                        # Intermediate masks losses are too costly to compute, we ignore them.
                        continue
                    kwargs = {}
                    if loss == 'labels':
                        # Logging is enabled only for the last layer
                        kwargs = {'log': False}
                    l_dict = self.get_loss(loss, aux_outputs, targets, indices, num_boxes, **kwargs)
                    l_dict = {k + f'_{i}': v for k, v in l_dict.items()}
                    losses.update(l_dict)

        return losses


class PostProcess(nn.Module):
    """ This module converts the model's output into the format expected by the coco api"""
    @torch.no_grad()
    def forward(self, outputs, target_sizes):
        """ Perform the computation
        Parameters:
            outputs: raw outputs of the model
            target_sizes: tensor of dimension [batch_size x 2] containing the size of each images of the batch
                          For evaluation, this must be the original image size (before any data augmentation)
                          For visualization, this should be the image size after data augment, but before padding
        """
        out_logits, out_bbox = outputs['pred_logits'], outputs['pred_boxes']

        assert len(out_logits) == len(target_sizes)
        assert target_sizes.shape[1] == 2

        prob = F.softmax(out_logits, -1)
        scores, labels = prob[..., :-1].max(-1)

        # convert to [x0, y0, x1, y1] format
        boxes = box_ops.box_cxcywh_to_xyxy(out_bbox)
        # and from relative [0, 1] to absolute [0, height] coordinates
        img_h, img_w = target_sizes.unbind(1)
        scale_fct = torch.stack([img_w, img_h, img_w, img_h], dim=1)
        boxes = boxes * scale_fct[:, None, :]

        results = [{'scores': s, 'labels': l, 'boxes': b} for s, l, b in zip(scores, labels, boxes)]

        return results


class MLP(nn.Module):
    """ Very simple multi-layer perceptron (also called FFN)"""

    def __init__(self, input_dim, hidden_dim, output_dim, num_layers):
        super().__init__()
        self.num_layers = num_layers
        h = [hidden_dim] * (num_layers - 1)
        self.layers = nn.ModuleList(nn.Linear(n, k) for n, k in zip([input_dim] + h, h + [output_dim]))

    def forward(self, x):
        for i, layer in enumerate(self.layers):
            x = F.relu(layer(x)) if i < self.num_layers - 1 else layer(x)
        return x


def build(args):
    # the `num_classes` naming here is somewhat misleading.
    # it indeed corresponds to `max_obj_id + 1`, where max_obj_id
    # is the maximum id for a class in your dataset. For example,
    # COCO has a max_obj_id of 90, so we pass `num_classes` to be 91.
    # As another example, for a dataset that has a single class with id 1,
    # you should pass `num_classes` to be 2 (max_obj_id + 1).
    # For more details on this, check the following discussion
    # https://github.com/facebookresearch/detr/issues/108#issuecomment-650269223
    num_classes = 20 if args.dataset_file != 'coco' else 91
    if args.dataset_file == "coco_panoptic":
        # for panoptic, we just add a num_classes that is large enough to hold
        # max_obj_id + 1, but the exact value doesn't really matter
        num_classes = 250
    device = torch.device(args.device)

    backbone = build_backbone(args)

    transformer = build_transformer(args)

    model = DETR(
        backbone,
        transformer,
        num_classes=num_classes,
        num_queries=args.num_queries,
        aux_loss=args.aux_loss,
    )
    if args.masks:
        model = DETRsegm(model, freeze_detr=(args.frozen_weights is not None))
    matcher = build_matcher(args)
    weight_dict = {'loss_ce': 1, 'loss_bbox': args.bbox_loss_coef}
    weight_dict['loss_giou'] = args.giou_loss_coef
    if args.masks:
        weight_dict["loss_mask"] = args.mask_loss_coef
        weight_dict["loss_dice"] = args.dice_loss_coef
    # TODO this is a hack
    if args.aux_loss:
        aux_weight_dict = {}
        for i in range(args.dec_layers - 1):
            aux_weight_dict.update({k + f'_{i}': v for k, v in weight_dict.items()})
        weight_dict.update(aux_weight_dict)

    losses = ['labels', 'boxes', 'cardinality']
    if args.masks:
        losses += ["masks"]
    criterion = SetCriterion(num_classes, matcher=matcher, weight_dict=weight_dict,
                             eos_coef=args.eos_coef, losses=losses)
    criterion.to(device)
    postprocessors = {'bbox': PostProcess()}
    if args.masks:
        postprocessors['segm'] = PostProcessSegm()
        if args.dataset_file == "coco_panoptic":
            is_thing_map = {i: i <= 90 for i in range(201)}
            postprocessors["panoptic"] = PostProcessPanoptic(is_thing_map, threshold=0.85)

    return model, criterion, postprocessors



File: models/matcher.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
Modules to compute the matching cost and solve the corresponding LSAP.
"""
import torch
from scipy.optimize import linear_sum_assignment
from torch import nn

from util.box_ops import box_cxcywh_to_xyxy, generalized_box_iou


class HungarianMatcher(nn.Module):
    """This class computes an assignment between the targets and the predictions of the network

    For efficiency reasons, the targets don't include the no_object. Because of this, in general,
    there are more predictions than targets. In this case, we do a 1-to-1 matching of the best predictions,
    while the others are un-matched (and thus treated as non-objects).
    """

    def __init__(self, cost_class: float = 1, cost_bbox: float = 1, cost_giou: float = 1):
        """Creates the matcher

        Params:
            cost_class: This is the relative weight of the classification error in the matching cost
            cost_bbox: This is the relative weight of the L1 error of the bounding box coordinates in the matching cost
            cost_giou: This is the relative weight of the giou loss of the bounding box in the matching cost
        """
        super().__init__()
        self.cost_class = cost_class
        self.cost_bbox = cost_bbox
        self.cost_giou = cost_giou
        assert cost_class != 0 or cost_bbox != 0 or cost_giou != 0, "all costs cant be 0"

    @torch.no_grad()
    def forward(self, outputs, targets):
        """ Performs the matching

        Params:
            outputs: This is a dict that contains at least these entries:
                 "pred_logits": Tensor of dim [batch_size, num_queries, num_classes] with the classification logits
                 "pred_boxes": Tensor of dim [batch_size, num_queries, 4] with the predicted box coordinates

            targets: This is a list of targets (len(targets) = batch_size), where each target is a dict containing:
                 "labels": Tensor of dim [num_target_boxes] (where num_target_boxes is the number of ground-truth
                           objects in the target) containing the class labels
                 "boxes": Tensor of dim [num_target_boxes, 4] containing the target box coordinates

        Returns:
            A list of size batch_size, containing tuples of (index_i, index_j) where:
                - index_i is the indices of the selected predictions (in order)
                - index_j is the indices of the corresponding selected targets (in order)
            For each batch element, it holds:
                len(index_i) = len(index_j) = min(num_queries, num_target_boxes)
        """
        bs, num_queries = outputs["pred_logits"].shape[:2]

        # We flatten to compute the cost matrices in a batch
        out_prob = outputs["pred_logits"].flatten(0, 1).softmax(-1)  # [batch_size * num_queries, num_classes]
        out_bbox = outputs["pred_boxes"].flatten(0, 1)  # [batch_size * num_queries, 4]

        # Also concat the target labels and boxes
        tgt_ids = torch.cat([v["labels"] for v in targets])
        tgt_bbox = torch.cat([v["boxes"] for v in targets])

        # Compute the classification cost. Contrary to the loss, we don't use the NLL,
        # but approximate it in 1 - proba[target class].
        # The 1 is a constant that doesn't change the matching, it can be ommitted.
        cost_class = -out_prob[:, tgt_ids]

        # Compute the L1 cost between boxes
        cost_bbox = torch.cdist(out_bbox, tgt_bbox, p=1)

        # Compute the giou cost betwen boxes
        cost_giou = -generalized_box_iou(box_cxcywh_to_xyxy(out_bbox), box_cxcywh_to_xyxy(tgt_bbox))

        # Final cost matrix
        C = self.cost_bbox * cost_bbox + self.cost_class * cost_class + self.cost_giou * cost_giou
        C = C.view(bs, num_queries, -1).cpu()

        sizes = [len(v["boxes"]) for v in targets]
        indices = [linear_sum_assignment(c[i]) for i, c in enumerate(C.split(sizes, -1))]
        return [(torch.as_tensor(i, dtype=torch.int64), torch.as_tensor(j, dtype=torch.int64)) for i, j in indices]


def build_matcher(args):
    return HungarianMatcher(cost_class=args.set_cost_class, cost_bbox=args.set_cost_bbox, cost_giou=args.set_cost_giou)



File: models/backbone.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
Backbone modules.
"""
from collections import OrderedDict

import torch
import torch.nn.functional as F
import torchvision
from torch import nn
from torchvision.models._utils import IntermediateLayerGetter
from typing import Dict, List

from util.misc import NestedTensor, is_main_process

from .position_encoding import build_position_encoding


class FrozenBatchNorm2d(torch.nn.Module):
    """
    BatchNorm2d where the batch statistics and the affine parameters are fixed.

    Copy-paste from torchvision.misc.ops with added eps before rqsrt,
    without which any other models than torchvision.models.resnet[18,34,50,101]
    produce nans.
    """

    def __init__(self, n):
        super(FrozenBatchNorm2d, self).__init__()
        self.register_buffer("weight", torch.ones(n))
        self.register_buffer("bias", torch.zeros(n))
        self.register_buffer("running_mean", torch.zeros(n))
        self.register_buffer("running_var", torch.ones(n))

    def _load_from_state_dict(self, state_dict, prefix, local_metadata, strict,
                              missing_keys, unexpected_keys, error_msgs):
        num_batches_tracked_key = prefix + 'num_batches_tracked'
        if num_batches_tracked_key in state_dict:
            del state_dict[num_batches_tracked_key]

        super(FrozenBatchNorm2d, self)._load_from_state_dict(
            state_dict, prefix, local_metadata, strict,
            missing_keys, unexpected_keys, error_msgs)

    def forward(self, x):
        # move reshapes to the beginning
        # to make it fuser-friendly
        w = self.weight.reshape(1, -1, 1, 1)
        b = self.bias.reshape(1, -1, 1, 1)
        rv = self.running_var.reshape(1, -1, 1, 1)
        rm = self.running_mean.reshape(1, -1, 1, 1)
        eps = 1e-5
        scale = w * (rv + eps).rsqrt()
        bias = b - rm * scale
        return x * scale + bias


class BackboneBase(nn.Module):

    def __init__(self, backbone: nn.Module, train_backbone: bool, num_channels: int, return_interm_layers: bool):
        super().__init__()
        for name, parameter in backbone.named_parameters():
            if not train_backbone or 'layer2' not in name and 'layer3' not in name and 'layer4' not in name:
                parameter.requires_grad_(False)
        if return_interm_layers:
            return_layers = {"layer1": "0", "layer2": "1", "layer3": "2", "layer4": "3"}
        else:
            return_layers = {'layer4': "0"}
        self.body = IntermediateLayerGetter(backbone, return_layers=return_layers)
        self.num_channels = num_channels

    def forward(self, tensor_list: NestedTensor):
        xs = self.body(tensor_list.tensors)
        out: Dict[str, NestedTensor] = {}
        for name, x in xs.items():
            m = tensor_list.mask
            assert m is not None
            mask = F.interpolate(m[None].float(), size=x.shape[-2:]).to(torch.bool)[0]
            out[name] = NestedTensor(x, mask)
        return out


class Backbone(BackboneBase):
    """ResNet backbone with frozen BatchNorm."""
    def __init__(self, name: str,
                 train_backbone: bool,
                 return_interm_layers: bool,
                 dilation: bool):
        backbone = getattr(torchvision.models, name)(
            replace_stride_with_dilation=[False, False, dilation],
            pretrained=is_main_process(), norm_layer=FrozenBatchNorm2d)
        num_channels = 512 if name in ('resnet18', 'resnet34') else 2048
        super().__init__(backbone, train_backbone, num_channels, return_interm_layers)


class Joiner(nn.Sequential):
    def __init__(self, backbone, position_embedding):
        super().__init__(backbone, position_embedding)

    def forward(self, tensor_list: NestedTensor):
        xs = self[0](tensor_list)
        out: List[NestedTensor] = []
        pos = []
        for name, x in xs.items():
            out.append(x)
            # position encoding
            pos.append(self[1](x).to(x.tensors.dtype))

        return out, pos


def build_backbone(args):
    position_embedding = build_position_encoding(args)
    train_backbone = args.lr_backbone > 0
    return_interm_layers = args.masks
    backbone = Backbone(args.backbone, train_backbone, return_interm_layers, args.dilation)
    model = Joiner(backbone, position_embedding)
    model.num_channels = backbone.num_channels
    return model



File: models/position_encoding.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
Various positional encodings for the transformer.
"""
import math
import torch
from torch import nn

from util.misc import NestedTensor


class PositionEmbeddingSine(nn.Module):
    """
    This is a more standard version of the position embedding, very similar to the one
    used by the Attention is all you need paper, generalized to work on images.
    """
    def __init__(self, num_pos_feats=64, temperature=10000, normalize=False, scale=None):
        super().__init__()
        self.num_pos_feats = num_pos_feats
        self.temperature = temperature
        self.normalize = normalize
        if scale is not None and normalize is False:
            raise ValueError("normalize should be True if scale is passed")
        if scale is None:
            scale = 2 * math.pi
        self.scale = scale

    def forward(self, tensor_list: NestedTensor):
        x = tensor_list.tensors
        mask = tensor_list.mask
        assert mask is not None
        not_mask = ~mask
        y_embed = not_mask.cumsum(1, dtype=torch.float32)
        x_embed = not_mask.cumsum(2, dtype=torch.float32)
        if self.normalize:
            eps = 1e-6
            y_embed = y_embed / (y_embed[:, -1:, :] + eps) * self.scale
            x_embed = x_embed / (x_embed[:, :, -1:] + eps) * self.scale

        dim_t = torch.arange(self.num_pos_feats, dtype=torch.float32, device=x.device)
        dim_t = self.temperature ** (2 * (dim_t // 2) / self.num_pos_feats)

        pos_x = x_embed[:, :, :, None] / dim_t
        pos_y = y_embed[:, :, :, None] / dim_t
        pos_x = torch.stack((pos_x[:, :, :, 0::2].sin(), pos_x[:, :, :, 1::2].cos()), dim=4).flatten(3)
        pos_y = torch.stack((pos_y[:, :, :, 0::2].sin(), pos_y[:, :, :, 1::2].cos()), dim=4).flatten(3)
        pos = torch.cat((pos_y, pos_x), dim=3).permute(0, 3, 1, 2)
        return pos


class PositionEmbeddingLearned(nn.Module):
    """
    Absolute pos embedding, learned.
    """
    def __init__(self, num_pos_feats=256):
        super().__init__()
        self.row_embed = nn.Embedding(50, num_pos_feats)
        self.col_embed = nn.Embedding(50, num_pos_feats)
        self.reset_parameters()

    def reset_parameters(self):
        nn.init.uniform_(self.row_embed.weight)
        nn.init.uniform_(self.col_embed.weight)

    def forward(self, tensor_list: NestedTensor):
        x = tensor_list.tensors
        h, w = x.shape[-2:]
        i = torch.arange(w, device=x.device)
        j = torch.arange(h, device=x.device)
        x_emb = self.col_embed(i)
        y_emb = self.row_embed(j)
        pos = torch.cat([
            x_emb.unsqueeze(0).repeat(h, 1, 1),
            y_emb.unsqueeze(1).repeat(1, w, 1),
        ], dim=-1).permute(2, 0, 1).unsqueeze(0).repeat(x.shape[0], 1, 1, 1)
        return pos


def build_position_encoding(args):
    N_steps = args.hidden_dim // 2
    if args.position_embedding in ('v2', 'sine'):
        # TODO find a better way of exposing other arguments
        position_embedding = PositionEmbeddingSine(N_steps, normalize=True)
    elif args.position_embedding in ('v3', 'learned'):
        position_embedding = PositionEmbeddingLearned(N_steps)
    else:
        raise ValueError(f"not supported {args.position_embedding}")

    return position_embedding



File: models/__init__.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
from .detr import build


def build_model(args):
    return build(args)



File: models/transformer.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
DETR Transformer class.

Copy-paste from torch.nn.Transformer with modifications:
    * positional encodings are passed in MHattention
    * extra LN at the end of encoder is removed
    * decoder returns a stack of activations from all decoding layers
"""
import copy
from typing import Optional, List

import torch
import torch.nn.functional as F
from torch import nn, Tensor


class Transformer(nn.Module):

    def __init__(self, d_model=512, nhead=8, num_encoder_layers=6,
                 num_decoder_layers=6, dim_feedforward=2048, dropout=0.1,
                 activation="relu", normalize_before=False,
                 return_intermediate_dec=False):
        super().__init__()

        encoder_layer = TransformerEncoderLayer(d_model, nhead, dim_feedforward,
                                                dropout, activation, normalize_before)
        encoder_norm = nn.LayerNorm(d_model) if normalize_before else None
        self.encoder = TransformerEncoder(encoder_layer, num_encoder_layers, encoder_norm)

        decoder_layer = TransformerDecoderLayer(d_model, nhead, dim_feedforward,
                                                dropout, activation, normalize_before)
        decoder_norm = nn.LayerNorm(d_model)
        self.decoder = TransformerDecoder(decoder_layer, num_decoder_layers, decoder_norm,
                                          return_intermediate=return_intermediate_dec)

        self._reset_parameters()

        self.d_model = d_model
        self.nhead = nhead

    def _reset_parameters(self):
        for p in self.parameters():
            if p.dim() > 1:
                nn.init.xavier_uniform_(p)

    def forward(self, src, mask, query_embed, pos_embed):
        # flatten NxCxHxW to HWxNxC
        bs, c, h, w = src.shape
        src = src.flatten(2).permute(2, 0, 1)
        pos_embed = pos_embed.flatten(2).permute(2, 0, 1)
        query_embed = query_embed.unsqueeze(1).repeat(1, bs, 1)
        mask = mask.flatten(1)

        tgt = torch.zeros_like(query_embed)
        memory = self.encoder(src, src_key_padding_mask=mask, pos=pos_embed)
        hs = self.decoder(tgt, memory, memory_key_padding_mask=mask,
                          pos=pos_embed, query_pos=query_embed)
        return hs.transpose(1, 2), memory.permute(1, 2, 0).view(bs, c, h, w)


class TransformerEncoder(nn.Module):

    def __init__(self, encoder_layer, num_layers, norm=None):
        super().__init__()
        self.layers = _get_clones(encoder_layer, num_layers)
        self.num_layers = num_layers
        self.norm = norm

    def forward(self, src,
                mask: Optional[Tensor] = None,
                src_key_padding_mask: Optional[Tensor] = None,
                pos: Optional[Tensor] = None):
        output = src

        for layer in self.layers:
            output = layer(output, src_mask=mask,
                           src_key_padding_mask=src_key_padding_mask, pos=pos)

        if self.norm is not None:
            output = self.norm(output)

        return output


class TransformerDecoder(nn.Module):

    def __init__(self, decoder_layer, num_layers, norm=None, return_intermediate=False):
        super().__init__()
        self.layers = _get_clones(decoder_layer, num_layers)
        self.num_layers = num_layers
        self.norm = norm
        self.return_intermediate = return_intermediate

    def forward(self, tgt, memory,
                tgt_mask: Optional[Tensor] = None,
                memory_mask: Optional[Tensor] = None,
                tgt_key_padding_mask: Optional[Tensor] = None,
                memory_key_padding_mask: Optional[Tensor] = None,
                pos: Optional[Tensor] = None,
                query_pos: Optional[Tensor] = None):
        output = tgt

        intermediate = []

        for layer in self.layers:
            output = layer(output, memory, tgt_mask=tgt_mask,
                           memory_mask=memory_mask,
                           tgt_key_padding_mask=tgt_key_padding_mask,
                           memory_key_padding_mask=memory_key_padding_mask,
                           pos=pos, query_pos=query_pos)
            if self.return_intermediate:
                intermediate.append(self.norm(output))

        if self.norm is not None:
            output = self.norm(output)
            if self.return_intermediate:
                intermediate.pop()
                intermediate.append(output)

        if self.return_intermediate:
            return torch.stack(intermediate)

        return output.unsqueeze(0)


class TransformerEncoderLayer(nn.Module):

    def __init__(self, d_model, nhead, dim_feedforward=2048, dropout=0.1,
                 activation="relu", normalize_before=False):
        super().__init__()
        self.self_attn = nn.MultiheadAttention(d_model, nhead, dropout=dropout)
        # Implementation of Feedforward model
        self.linear1 = nn.Linear(d_model, dim_feedforward)
        self.dropout = nn.Dropout(dropout)
        self.linear2 = nn.Linear(dim_feedforward, d_model)

        self.norm1 = nn.LayerNorm(d_model)
        self.norm2 = nn.LayerNorm(d_model)
        self.dropout1 = nn.Dropout(dropout)
        self.dropout2 = nn.Dropout(dropout)

        self.activation = _get_activation_fn(activation)
        self.normalize_before = normalize_before

    def with_pos_embed(self, tensor, pos: Optional[Tensor]):
        return tensor if pos is None else tensor + pos

    def forward_post(self,
                     src,
                     src_mask: Optional[Tensor] = None,
                     src_key_padding_mask: Optional[Tensor] = None,
                     pos: Optional[Tensor] = None):
        q = k = self.with_pos_embed(src, pos)
        src2 = self.self_attn(q, k, value=src, attn_mask=src_mask,
                              key_padding_mask=src_key_padding_mask)[0]
        src = src + self.dropout1(src2)
        src = self.norm1(src)
        src2 = self.linear2(self.dropout(self.activation(self.linear1(src))))
        src = src + self.dropout2(src2)
        src = self.norm2(src)
        return src

    def forward_pre(self, src,
                    src_mask: Optional[Tensor] = None,
                    src_key_padding_mask: Optional[Tensor] = None,
                    pos: Optional[Tensor] = None):
        src2 = self.norm1(src)
        q = k = self.with_pos_embed(src2, pos)
        src2 = self.self_attn(q, k, value=src2, attn_mask=src_mask,
                              key_padding_mask=src_key_padding_mask)[0]
        src = src + self.dropout1(src2)
        src2 = self.norm2(src)
        src2 = self.linear2(self.dropout(self.activation(self.linear1(src2))))
        src = src + self.dropout2(src2)
        return src

    def forward(self, src,
                src_mask: Optional[Tensor] = None,
                src_key_padding_mask: Optional[Tensor] = None,
                pos: Optional[Tensor] = None):
        if self.normalize_before:
            return self.forward_pre(src, src_mask, src_key_padding_mask, pos)
        return self.forward_post(src, src_mask, src_key_padding_mask, pos)


class TransformerDecoderLayer(nn.Module):

    def __init__(self, d_model, nhead, dim_feedforward=2048, dropout=0.1,
                 activation="relu", normalize_before=False):
        super().__init__()
        self.self_attn = nn.MultiheadAttention(d_model, nhead, dropout=dropout)
        self.multihead_attn = nn.MultiheadAttention(d_model, nhead, dropout=dropout)
        # Implementation of Feedforward model
        self.linear1 = nn.Linear(d_model, dim_feedforward)
        self.dropout = nn.Dropout(dropout)
        self.linear2 = nn.Linear(dim_feedforward, d_model)

        self.norm1 = nn.LayerNorm(d_model)
        self.norm2 = nn.LayerNorm(d_model)
        self.norm3 = nn.LayerNorm(d_model)
        self.dropout1 = nn.Dropout(dropout)
        self.dropout2 = nn.Dropout(dropout)
        self.dropout3 = nn.Dropout(dropout)

        self.activation = _get_activation_fn(activation)
        self.normalize_before = normalize_before

    def with_pos_embed(self, tensor, pos: Optional[Tensor]):
        return tensor if pos is None else tensor + pos

    def forward_post(self, tgt, memory,
                     tgt_mask: Optional[Tensor] = None,
                     memory_mask: Optional[Tensor] = None,
                     tgt_key_padding_mask: Optional[Tensor] = None,
                     memory_key_padding_mask: Optional[Tensor] = None,
                     pos: Optional[Tensor] = None,
                     query_pos: Optional[Tensor] = None):
        q = k = self.with_pos_embed(tgt, query_pos)
        tgt2 = self.self_attn(q, k, value=tgt, attn_mask=tgt_mask,
                              key_padding_mask=tgt_key_padding_mask)[0]
        tgt = tgt + self.dropout1(tgt2)
        tgt = self.norm1(tgt)
        tgt2 = self.multihead_attn(query=self.with_pos_embed(tgt, query_pos),
                                   key=self.with_pos_embed(memory, pos),
                                   value=memory, attn_mask=memory_mask,
                                   key_padding_mask=memory_key_padding_mask)[0]
        tgt = tgt + self.dropout2(tgt2)
        tgt = self.norm2(tgt)
        tgt2 = self.linear2(self.dropout(self.activation(self.linear1(tgt))))
        tgt = tgt + self.dropout3(tgt2)
        tgt = self.norm3(tgt)
        return tgt

    def forward_pre(self, tgt, memory,
                    tgt_mask: Optional[Tensor] = None,
                    memory_mask: Optional[Tensor] = None,
                    tgt_key_padding_mask: Optional[Tensor] = None,
                    memory_key_padding_mask: Optional[Tensor] = None,
                    pos: Optional[Tensor] = None,
                    query_pos: Optional[Tensor] = None):
        tgt2 = self.norm1(tgt)
        q = k = self.with_pos_embed(tgt2, query_pos)
        tgt2 = self.self_attn(q, k, value=tgt2, attn_mask=tgt_mask,
                              key_padding_mask=tgt_key_padding_mask)[0]
        tgt = tgt + self.dropout1(tgt2)
        tgt2 = self.norm2(tgt)
        tgt2 = self.multihead_attn(query=self.with_pos_embed(tgt2, query_pos),
                                   key=self.with_pos_embed(memory, pos),
                                   value=memory, attn_mask=memory_mask,
                                   key_padding_mask=memory_key_padding_mask)[0]
        tgt = tgt + self.dropout2(tgt2)
        tgt2 = self.norm3(tgt)
        tgt2 = self.linear2(self.dropout(self.activation(self.linear1(tgt2))))
        tgt = tgt + self.dropout3(tgt2)
        return tgt

    def forward(self, tgt, memory,
                tgt_mask: Optional[Tensor] = None,
                memory_mask: Optional[Tensor] = None,
                tgt_key_padding_mask: Optional[Tensor] = None,
                memory_key_padding_mask: Optional[Tensor] = None,
                pos: Optional[Tensor] = None,
                query_pos: Optional[Tensor] = None):
        if self.normalize_before:
            return self.forward_pre(tgt, memory, tgt_mask, memory_mask,
                                    tgt_key_padding_mask, memory_key_padding_mask, pos, query_pos)
        return self.forward_post(tgt, memory, tgt_mask, memory_mask,
                                 tgt_key_padding_mask, memory_key_padding_mask, pos, query_pos)


def _get_clones(module, N):
    return nn.ModuleList([copy.deepcopy(module) for i in range(N)])


def build_transformer(args):
    return Transformer(
        d_model=args.hidden_dim,
        dropout=args.dropout,
        nhead=args.nheads,
        dim_feedforward=args.dim_feedforward,
        num_encoder_layers=args.enc_layers,
        num_decoder_layers=args.dec_layers,
        normalize_before=args.pre_norm,
        return_intermediate_dec=True,
    )


def _get_activation_fn(activation):
    """Return an activation function given a string"""
    if activation == "relu":
        return F.relu
    if activation == "gelu":
        return F.gelu
    if activation == "glu":
        return F.glu
    raise RuntimeError(F"activation should be relu/gelu, not {activation}.")



File: models/segmentation.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
This file provides the definition of the convolutional heads used to predict masks, as well as the losses
"""
import io
from collections import defaultdict
from typing import List, Optional

import torch
import torch.nn as nn
import torch.nn.functional as F
from torch import Tensor
from PIL import Image

import util.box_ops as box_ops
from util.misc import NestedTensor, interpolate, nested_tensor_from_tensor_list

try:
    from panopticapi.utils import id2rgb, rgb2id
except ImportError:
    pass


class DETRsegm(nn.Module):
    def __init__(self, detr, freeze_detr=False):
        super().__init__()
        self.detr = detr

        if freeze_detr:
            for p in self.parameters():
                p.requires_grad_(False)

        hidden_dim, nheads = detr.transformer.d_model, detr.transformer.nhead
        self.bbox_attention = MHAttentionMap(hidden_dim, hidden_dim, nheads, dropout=0.0)
        self.mask_head = MaskHeadSmallConv(hidden_dim + nheads, [1024, 512, 256], hidden_dim)

    def forward(self, samples: NestedTensor):
        if isinstance(samples, (list, torch.Tensor)):
            samples = nested_tensor_from_tensor_list(samples)
        features, pos = self.detr.backbone(samples)

        bs = features[-1].tensors.shape[0]

        src, mask = features[-1].decompose()
        assert mask is not None
        src_proj = self.detr.input_proj(src)
        hs, memory = self.detr.transformer(src_proj, mask, self.detr.query_embed.weight, pos[-1])

        outputs_class = self.detr.class_embed(hs)
        outputs_coord = self.detr.bbox_embed(hs).sigmoid()
        out = {"pred_logits": outputs_class[-1], "pred_boxes": outputs_coord[-1]}
        if self.detr.aux_loss:
            out['aux_outputs'] = self.detr._set_aux_loss(outputs_class, outputs_coord)

        # FIXME h_boxes takes the last one computed, keep this in mind
        bbox_mask = self.bbox_attention(hs[-1], memory, mask=mask)

        seg_masks = self.mask_head(src_proj, bbox_mask, [features[2].tensors, features[1].tensors, features[0].tensors])
        outputs_seg_masks = seg_masks.view(bs, self.detr.num_queries, seg_masks.shape[-2], seg_masks.shape[-1])

        out["pred_masks"] = outputs_seg_masks
        return out


def _expand(tensor, length: int):
    return tensor.unsqueeze(1).repeat(1, int(length), 1, 1, 1).flatten(0, 1)


class MaskHeadSmallConv(nn.Module):
    """
    Simple convolutional head, using group norm.
    Upsampling is done using a FPN approach
    """

    def __init__(self, dim, fpn_dims, context_dim):
        super().__init__()

        inter_dims = [dim, context_dim // 2, context_dim // 4, context_dim // 8, context_dim // 16, context_dim // 64]
        self.lay1 = torch.nn.Conv2d(dim, dim, 3, padding=1)
        self.gn1 = torch.nn.GroupNorm(8, dim)
        self.lay2 = torch.nn.Conv2d(dim, inter_dims[1], 3, padding=1)
        self.gn2 = torch.nn.GroupNorm(8, inter_dims[1])
        self.lay3 = torch.nn.Conv2d(inter_dims[1], inter_dims[2], 3, padding=1)
        self.gn3 = torch.nn.GroupNorm(8, inter_dims[2])
        self.lay4 = torch.nn.Conv2d(inter_dims[2], inter_dims[3], 3, padding=1)
        self.gn4 = torch.nn.GroupNorm(8, inter_dims[3])
        self.lay5 = torch.nn.Conv2d(inter_dims[3], inter_dims[4], 3, padding=1)
        self.gn5 = torch.nn.GroupNorm(8, inter_dims[4])
        self.out_lay = torch.nn.Conv2d(inter_dims[4], 1, 3, padding=1)

        self.dim = dim

        self.adapter1 = torch.nn.Conv2d(fpn_dims[0], inter_dims[1], 1)
        self.adapter2 = torch.nn.Conv2d(fpn_dims[1], inter_dims[2], 1)
        self.adapter3 = torch.nn.Conv2d(fpn_dims[2], inter_dims[3], 1)

        for m in self.modules():
            if isinstance(m, nn.Conv2d):
                nn.init.kaiming_uniform_(m.weight, a=1)
                nn.init.constant_(m.bias, 0)

    def forward(self, x: Tensor, bbox_mask: Tensor, fpns: List[Tensor]):
        x = torch.cat([_expand(x, bbox_mask.shape[1]), bbox_mask.flatten(0, 1)], 1)

        x = self.lay1(x)
        x = self.gn1(x)
        x = F.relu(x)
        x = self.lay2(x)
        x = self.gn2(x)
        x = F.relu(x)

        cur_fpn = self.adapter1(fpns[0])
        if cur_fpn.size(0) != x.size(0):
            cur_fpn = _expand(cur_fpn, x.size(0) // cur_fpn.size(0))
        x = cur_fpn + F.interpolate(x, size=cur_fpn.shape[-2:], mode="nearest")
        x = self.lay3(x)
        x = self.gn3(x)
        x = F.relu(x)

        cur_fpn = self.adapter2(fpns[1])
        if cur_fpn.size(0) != x.size(0):
            cur_fpn = _expand(cur_fpn, x.size(0) // cur_fpn.size(0))
        x = cur_fpn + F.interpolate(x, size=cur_fpn.shape[-2:], mode="nearest")
        x = self.lay4(x)
        x = self.gn4(x)
        x = F.relu(x)

        cur_fpn = self.adapter3(fpns[2])
        if cur_fpn.size(0) != x.size(0):
            cur_fpn = _expand(cur_fpn, x.size(0) // cur_fpn.size(0))
        x = cur_fpn + F.interpolate(x, size=cur_fpn.shape[-2:], mode="nearest")
        x = self.lay5(x)
        x = self.gn5(x)
        x = F.relu(x)

        x = self.out_lay(x)
        return x


class MHAttentionMap(nn.Module):
    """This is a 2D attention module, which only returns the attention softmax (no multiplication by value)"""

    def __init__(self, query_dim, hidden_dim, num_heads, dropout=0.0, bias=True):
        super().__init__()
        self.num_heads = num_heads
        self.hidden_dim = hidden_dim
        self.dropout = nn.Dropout(dropout)

        self.q_linear = nn.Linear(query_dim, hidden_dim, bias=bias)
        self.k_linear = nn.Linear(query_dim, hidden_dim, bias=bias)

        nn.init.zeros_(self.k_linear.bias)
        nn.init.zeros_(self.q_linear.bias)
        nn.init.xavier_uniform_(self.k_linear.weight)
        nn.init.xavier_uniform_(self.q_linear.weight)
        self.normalize_fact = float(hidden_dim / self.num_heads) ** -0.5

    def forward(self, q, k, mask: Optional[Tensor] = None):
        q = self.q_linear(q)
        k = F.conv2d(k, self.k_linear.weight.unsqueeze(-1).unsqueeze(-1), self.k_linear.bias)
        qh = q.view(q.shape[0], q.shape[1], self.num_heads, self.hidden_dim // self.num_heads)
        kh = k.view(k.shape[0], self.num_heads, self.hidden_dim // self.num_heads, k.shape[-2], k.shape[-1])
        weights = torch.einsum("bqnc,bnchw->bqnhw", qh * self.normalize_fact, kh)

        if mask is not None:
            weights.masked_fill_(mask.unsqueeze(1).unsqueeze(1), float("-inf"))
        weights = F.softmax(weights.flatten(2), dim=-1).view(weights.size())
        weights = self.dropout(weights)
        return weights


def dice_loss(inputs, targets, num_boxes):
    """
    Compute the DICE loss, similar to generalized IOU for masks
    Args:
        inputs: A float tensor of arbitrary shape.
                The predictions for each example.
        targets: A float tensor with the same shape as inputs. Stores the binary
                 classification label for each element in inputs
                (0 for the negative class and 1 for the positive class).
    """
    inputs = inputs.sigmoid()
    inputs = inputs.flatten(1)
    numerator = 2 * (inputs * targets).sum(1)
    denominator = inputs.sum(-1) + targets.sum(-1)
    loss = 1 - (numerator + 1) / (denominator + 1)
    return loss.sum() / num_boxes


def sigmoid_focal_loss(inputs, targets, num_boxes, alpha: float = 0.25, gamma: float = 2):
    """
    Loss used in RetinaNet for dense detection: https://arxiv.org/abs/1708.02002.
    Args:
        inputs: A float tensor of arbitrary shape.
                The predictions for each example.
        targets: A float tensor with the same shape as inputs. Stores the binary
                 classification label for each element in inputs
                (0 for the negative class and 1 for the positive class).
        alpha: (optional) Weighting factor in range (0,1) to balance
                positive vs negative examples. Default = -1 (no weighting).
        gamma: Exponent of the modulating factor (1 - p_t) to
               balance easy vs hard examples.
    Returns:
        Loss tensor
    """
    prob = inputs.sigmoid()
    ce_loss = F.binary_cross_entropy_with_logits(inputs, targets, reduction="none")
    p_t = prob * targets + (1 - prob) * (1 - targets)
    loss = ce_loss * ((1 - p_t) ** gamma)

    if alpha >= 0:
        alpha_t = alpha * targets + (1 - alpha) * (1 - targets)
        loss = alpha_t * loss

    return loss.mean(1).sum() / num_boxes


class PostProcessSegm(nn.Module):
    def __init__(self, threshold=0.5):
        super().__init__()
        self.threshold = threshold

    @torch.no_grad()
    def forward(self, results, outputs, orig_target_sizes, max_target_sizes):
        assert len(orig_target_sizes) == len(max_target_sizes)
        max_h, max_w = max_target_sizes.max(0)[0].tolist()
        outputs_masks = outputs["pred_masks"].squeeze(2)
        outputs_masks = F.interpolate(outputs_masks, size=(max_h, max_w), mode="bilinear", align_corners=False)
        outputs_masks = (outputs_masks.sigmoid() > self.threshold).cpu()

        for i, (cur_mask, t, tt) in enumerate(zip(outputs_masks, max_target_sizes, orig_target_sizes)):
            img_h, img_w = t[0], t[1]
            results[i]["masks"] = cur_mask[:, :img_h, :img_w].unsqueeze(1)
            results[i]["masks"] = F.interpolate(
                results[i]["masks"].float(), size=tuple(tt.tolist()), mode="nearest"
            ).byte()

        return results


class PostProcessPanoptic(nn.Module):
    """This class converts the output of the model to the final panoptic result, in the format expected by the
    coco panoptic API """

    def __init__(self, is_thing_map, threshold=0.85):
        """
        Parameters:
           is_thing_map: This is a whose keys are the class ids, and the values a boolean indicating whether
                          the class is  a thing (True) or a stuff (False) class
           threshold: confidence threshold: segments with confidence lower than this will be deleted
        """
        super().__init__()
        self.threshold = threshold
        self.is_thing_map = is_thing_map

    def forward(self, outputs, processed_sizes, target_sizes=None):
        """ This function computes the panoptic prediction from the model's predictions.
        Parameters:
            outputs: This is a dict coming directly from the model. See the model doc for the content.
            processed_sizes: This is a list of tuples (or torch tensors) of sizes of the images that were passed to the
                             model, ie the size after data augmentation but before batching.
            target_sizes: This is a list of tuples (or torch tensors) corresponding to the requested final size
                          of each prediction. If left to None, it will default to the processed_sizes
            """
        if target_sizes is None:
            target_sizes = processed_sizes
        assert len(processed_sizes) == len(target_sizes)
        out_logits, raw_masks, raw_boxes = outputs["pred_logits"], outputs["pred_masks"], outputs["pred_boxes"]
        assert len(out_logits) == len(raw_masks) == len(target_sizes)
        preds = []

        def to_tuple(tup):
            if isinstance(tup, tuple):
                return tup
            return tuple(tup.cpu().tolist())

        for cur_logits, cur_masks, cur_boxes, size, target_size in zip(
            out_logits, raw_masks, raw_boxes, processed_sizes, target_sizes
        ):
            # we filter empty queries and detection below threshold
            scores, labels = cur_logits.softmax(-1).max(-1)
            keep = labels.ne(outputs["pred_logits"].shape[-1] - 1) & (scores > self.threshold)
            cur_scores, cur_classes = cur_logits.softmax(-1).max(-1)
            cur_scores = cur_scores[keep]
            cur_classes = cur_classes[keep]
            cur_masks = cur_masks[keep]
            cur_masks = interpolate(cur_masks[:, None], to_tuple(size), mode="bilinear").squeeze(1)
            cur_boxes = box_ops.box_cxcywh_to_xyxy(cur_boxes[keep])

            h, w = cur_masks.shape[-2:]
            assert len(cur_boxes) == len(cur_classes)

            # It may be that we have several predicted masks for the same stuff class.
            # In the following, we track the list of masks ids for each stuff class (they are merged later on)
            cur_masks = cur_masks.flatten(1)
            stuff_equiv_classes = defaultdict(lambda: [])
            for k, label in enumerate(cur_classes):
                if not self.is_thing_map[label.item()]:
                    stuff_equiv_classes[label.item()].append(k)

            def get_ids_area(masks, scores, dedup=False):
                # This helper function creates the final panoptic segmentation image
                # It also returns the area of the masks that appears on the image

                m_id = masks.transpose(0, 1).softmax(-1)

                if m_id.shape[-1] == 0:
                    # We didn't detect any mask :(
                    m_id = torch.zeros((h, w), dtype=torch.long, device=m_id.device)
                else:
                    m_id = m_id.argmax(-1).view(h, w)

                if dedup:
                    # Merge the masks corresponding to the same stuff class
                    for equiv in stuff_equiv_classes.values():
                        if len(equiv) > 1:
                            for eq_id in equiv:
                                m_id.masked_fill_(m_id.eq(eq_id), equiv[0])

                final_h, final_w = to_tuple(target_size)

                seg_img = Image.fromarray(id2rgb(m_id.view(h, w).cpu().numpy()))
                seg_img = seg_img.resize(size=(final_w, final_h), resample=Image.NEAREST)

                np_seg_img = (
                    torch.ByteTensor(torch.ByteStorage.from_buffer(seg_img.tobytes())).view(final_h, final_w, 3).numpy()
                )
                m_id = torch.from_numpy(rgb2id(np_seg_img))

                area = []
                for i in range(len(scores)):
                    area.append(m_id.eq(i).sum().item())
                return area, seg_img

            area, seg_img = get_ids_area(cur_masks, cur_scores, dedup=True)
            if cur_classes.numel() > 0:
                # We know filter empty masks as long as we find some
                while True:
                    filtered_small = torch.as_tensor(
                        [area[i] <= 4 for i, c in enumerate(cur_classes)], dtype=torch.bool, device=keep.device
                    )
                    if filtered_small.any().item():
                        cur_scores = cur_scores[~filtered_small]
                        cur_classes = cur_classes[~filtered_small]
                        cur_masks = cur_masks[~filtered_small]
                        area, seg_img = get_ids_area(cur_masks, cur_scores)
                    else:
                        break

            else:
                cur_classes = torch.ones(1, dtype=torch.long, device=cur_classes.device)

            segments_info = []
            for i, a in enumerate(area):
                cat = cur_classes[i].item()
                segments_info.append({"id": i, "isthing": self.is_thing_map[cat], "category_id": cat, "area": a})
            del cur_classes

            with io.BytesIO() as out:
                seg_img.save(out, format="PNG")
                predictions = {"png_string": out.getvalue(), "segments_info": segments_info}
            preds.append(predictions)
        return preds



File: d2/converter.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
Helper script to convert models trained with the main version of DETR to be used with the Detectron2 version.
"""
import json
import argparse

import numpy as np
import torch


def parse_args():
    parser = argparse.ArgumentParser("D2 model converter")

    parser.add_argument("--source_model", default="", type=str, help="Path or url to the DETR model to convert")
    parser.add_argument("--output_model", default="", type=str, help="Path where to save the converted model")
    return parser.parse_args()


def main():
    args = parse_args()

    # D2 expects contiguous classes, so we need to remap the 92 classes from DETR
    # fmt: off
    coco_idx = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
                27, 28, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51,
                52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 67, 70, 72, 73, 74, 75, 76, 77,
                78, 79, 80, 81, 82, 84, 85, 86, 87, 88, 89, 90, 91]
    # fmt: on

    coco_idx = np.array(coco_idx)

    if args.source_model.startswith("https"):
        checkpoint = torch.hub.load_state_dict_from_url(args.source_model, map_location="cpu", check_hash=True)
    else:
        checkpoint = torch.load(args.source_model, map_location="cpu")
    model_to_convert = checkpoint["model"]

    model_converted = {}
    for k in model_to_convert.keys():
        old_k = k
        if "backbone" in k:
            k = k.replace("backbone.0.body.", "")
            if "layer" not in k:
                k = "stem." + k
            for t in [1, 2, 3, 4]:
                k = k.replace(f"layer{t}", f"res{t + 1}")
            for t in [1, 2, 3]:
                k = k.replace(f"bn{t}", f"conv{t}.norm")
            k = k.replace("downsample.0", "shortcut")
            k = k.replace("downsample.1", "shortcut.norm")
            k = "backbone.0.backbone." + k
        k = "detr." + k
        print(old_k, "->", k)
        if "class_embed" in old_k:
            v = model_to_convert[old_k].detach()
            if v.shape[0] == 92:
                shape_old = v.shape
                model_converted[k] = v[coco_idx]
                print("Head conversion: changing shape from {} to {}".format(shape_old, model_converted[k].shape))
                continue
        model_converted[k] = model_to_convert[old_k].detach()

    model_to_save = {"model": model_converted}
    torch.save(model_to_save, args.output_model)


if __name__ == "__main__":
    main()



File: d2/train_net.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
"""
DETR Training Script.

This script is a simplified version of the training script in detectron2/tools.
"""
import os
import sys
import itertools

# fmt: off
sys.path.insert(1, os.path.join(sys.path[0], '..'))
# fmt: on

import time
from typing import Any, Dict, List, Set

import torch

import detectron2.utils.comm as comm
from d2.detr import DetrDatasetMapper, add_detr_config
from detectron2.checkpoint import DetectionCheckpointer
from detectron2.config import get_cfg
from detectron2.data import MetadataCatalog, build_detection_train_loader
from detectron2.engine import DefaultTrainer, default_argument_parser, default_setup, launch
from detectron2.evaluation import COCOEvaluator, verify_results

from detectron2.solver.build import maybe_add_gradient_clipping


class Trainer(DefaultTrainer):
    """
    Extension of the Trainer class adapted to DETR.
    """

    @classmethod
    def build_evaluator(cls, cfg, dataset_name, output_folder=None):
        """
        Create evaluator(s) for a given dataset.
        This uses the special metadata "evaluator_type" associated with each builtin dataset.
        For your own dataset, you can simply create an evaluator manually in your
        script and do not have to worry about the hacky if-else logic here.
        """
        if output_folder is None:
            output_folder = os.path.join(cfg.OUTPUT_DIR, "inference")
        return COCOEvaluator(dataset_name, cfg, True, output_folder)

    @classmethod
    def build_train_loader(cls, cfg):
        if "Detr" == cfg.MODEL.META_ARCHITECTURE:
            mapper = DetrDatasetMapper(cfg, True)
        else:
            mapper = None
        return build_detection_train_loader(cfg, mapper=mapper)

    @classmethod
    def build_optimizer(cls, cfg, model):
        params: List[Dict[str, Any]] = []
        memo: Set[torch.nn.parameter.Parameter] = set()
        for key, value in model.named_parameters(recurse=True):
            if not value.requires_grad:
                continue
            # Avoid duplicating parameters
            if value in memo:
                continue
            memo.add(value)
            lr = cfg.SOLVER.BASE_LR
            weight_decay = cfg.SOLVER.WEIGHT_DECAY
            if "backbone" in key:
                lr = lr * cfg.SOLVER.BACKBONE_MULTIPLIER
            params += [{"params": [value], "lr": lr, "weight_decay": weight_decay}]

        def maybe_add_full_model_gradient_clipping(optim):  # optim: the optimizer class
            # detectron2 doesn't have full model gradient clipping now
            clip_norm_val = cfg.SOLVER.CLIP_GRADIENTS.CLIP_VALUE
            enable = (
                cfg.SOLVER.CLIP_GRADIENTS.ENABLED
                and cfg.SOLVER.CLIP_GRADIENTS.CLIP_TYPE == "full_model"
                and clip_norm_val > 0.0
            )

            class FullModelGradientClippingOptimizer(optim):
                def step(self, closure=None):
                    all_params = itertools.chain(*[x["params"] for x in self.param_groups])
                    torch.nn.utils.clip_grad_norm_(all_params, clip_norm_val)
                    super().step(closure=closure)

            return FullModelGradientClippingOptimizer if enable else optim

        optimizer_type = cfg.SOLVER.OPTIMIZER
        if optimizer_type == "SGD":
            optimizer = maybe_add_full_model_gradient_clipping(torch.optim.SGD)(
                params, cfg.SOLVER.BASE_LR, momentum=cfg.SOLVER.MOMENTUM
            )
        elif optimizer_type == "ADAMW":
            optimizer = maybe_add_full_model_gradient_clipping(torch.optim.AdamW)(
                params, cfg.SOLVER.BASE_LR
            )
        else:
            raise NotImplementedError(f"no optimizer type {optimizer_type}")
        if not cfg.SOLVER.CLIP_GRADIENTS.CLIP_TYPE == "full_model":
            optimizer = maybe_add_gradient_clipping(cfg, optimizer)
        return optimizer


def setup(args):
    """
    Create configs and perform basic setups.
    """
    cfg = get_cfg()
    add_detr_config(cfg)
    cfg.merge_from_file(args.config_file)
    cfg.merge_from_list(args.opts)
    cfg.freeze()
    default_setup(cfg, args)
    return cfg


def main(args):
    cfg = setup(args)

    if args.eval_only:
        model = Trainer.build_model(cfg)
        DetectionCheckpointer(model, save_dir=cfg.OUTPUT_DIR).resume_or_load(cfg.MODEL.WEIGHTS, resume=args.resume)
        res = Trainer.test(cfg, model)
        if comm.is_main_process():
            verify_results(cfg, res)
        return res

    trainer = Trainer(cfg)
    trainer.resume_or_load(resume=args.resume)
    return trainer.train()


if __name__ == "__main__":
    args = default_argument_parser().parse_args()
    print("Command Line Args:", args)
    launch(
        main,
        args.num_gpus,
        num_machines=args.num_machines,
        machine_rank=args.machine_rank,
        dist_url=args.dist_url,
        args=(args,),
    )



File: d2/detr/detr.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
import logging
import math
from typing import List

import numpy as np
import torch
import torch.distributed as dist
import torch.nn.functional as F
from scipy.optimize import linear_sum_assignment
from torch import nn

from detectron2.layers import ShapeSpec
from detectron2.modeling import META_ARCH_REGISTRY, build_backbone, detector_postprocess
from detectron2.structures import Boxes, ImageList, Instances, BitMasks, PolygonMasks
from detectron2.utils.logger import log_first_n
from fvcore.nn import giou_loss, smooth_l1_loss
from models.backbone import Joiner
from models.detr import DETR, SetCriterion
from models.matcher import HungarianMatcher
from models.position_encoding import PositionEmbeddingSine
from models.transformer import Transformer
from models.segmentation import DETRsegm, PostProcessPanoptic, PostProcessSegm
from util.box_ops import box_cxcywh_to_xyxy, box_xyxy_to_cxcywh
from util.misc import NestedTensor
from datasets.coco import convert_coco_poly_to_mask

__all__ = ["Detr"]


class MaskedBackbone(nn.Module):
    """ This is a thin wrapper around D2's backbone to provide padding masking"""

    def __init__(self, cfg):
        super().__init__()
        self.backbone = build_backbone(cfg)
        backbone_shape = self.backbone.output_shape()
        self.feature_strides = [backbone_shape[f].stride for f in backbone_shape.keys()]
        self.num_channels = backbone_shape[list(backbone_shape.keys())[-1]].channels

    def forward(self, images):
        features = self.backbone(images.tensor)
        masks = self.mask_out_padding(
            [features_per_level.shape for features_per_level in features.values()],
            images.image_sizes,
            images.tensor.device,
        )
        assert len(features) == len(masks)
        for i, k in enumerate(features.keys()):
            features[k] = NestedTensor(features[k], masks[i])
        return features

    def mask_out_padding(self, feature_shapes, image_sizes, device):
        masks = []
        assert len(feature_shapes) == len(self.feature_strides)
        for idx, shape in enumerate(feature_shapes):
            N, _, H, W = shape
            masks_per_feature_level = torch.ones((N, H, W), dtype=torch.bool, device=device)
            for img_idx, (h, w) in enumerate(image_sizes):
                masks_per_feature_level[
                    img_idx,
                    : int(np.ceil(float(h) / self.feature_strides[idx])),
                    : int(np.ceil(float(w) / self.feature_strides[idx])),
                ] = 0
            masks.append(masks_per_feature_level)
        return masks


@META_ARCH_REGISTRY.register()
class Detr(nn.Module):
    """
    Implement Detr
    """

    def __init__(self, cfg):
        super().__init__()

        self.device = torch.device(cfg.MODEL.DEVICE)

        self.num_classes = cfg.MODEL.DETR.NUM_CLASSES
        self.mask_on = cfg.MODEL.MASK_ON
        hidden_dim = cfg.MODEL.DETR.HIDDEN_DIM
        num_queries = cfg.MODEL.DETR.NUM_OBJECT_QUERIES
        # Transformer parameters:
        nheads = cfg.MODEL.DETR.NHEADS
        dropout = cfg.MODEL.DETR.DROPOUT
        dim_feedforward = cfg.MODEL.DETR.DIM_FEEDFORWARD
        enc_layers = cfg.MODEL.DETR.ENC_LAYERS
        dec_layers = cfg.MODEL.DETR.DEC_LAYERS
        pre_norm = cfg.MODEL.DETR.PRE_NORM

        # Loss parameters:
        giou_weight = cfg.MODEL.DETR.GIOU_WEIGHT
        l1_weight = cfg.MODEL.DETR.L1_WEIGHT
        deep_supervision = cfg.MODEL.DETR.DEEP_SUPERVISION
        no_object_weight = cfg.MODEL.DETR.NO_OBJECT_WEIGHT

        N_steps = hidden_dim // 2
        d2_backbone = MaskedBackbone(cfg)
        backbone = Joiner(d2_backbone, PositionEmbeddingSine(N_steps, normalize=True))
        backbone.num_channels = d2_backbone.num_channels

        transformer = Transformer(
            d_model=hidden_dim,
            dropout=dropout,
            nhead=nheads,
            dim_feedforward=dim_feedforward,
            num_encoder_layers=enc_layers,
            num_decoder_layers=dec_layers,
            normalize_before=pre_norm,
            return_intermediate_dec=deep_supervision,
        )

        self.detr = DETR(
            backbone, transformer, num_classes=self.num_classes, num_queries=num_queries, aux_loss=deep_supervision
        )
        if self.mask_on:
            frozen_weights = cfg.MODEL.DETR.FROZEN_WEIGHTS
            if frozen_weights != '':
                print("LOAD pre-trained weights")
                weight = torch.load(frozen_weights, map_location=lambda storage, loc: storage)['model']
                new_weight = {}
                for k, v in weight.items():
                    if 'detr.' in k:
                        new_weight[k.replace('detr.', '')] = v
                    else:
                        print(f"Skipping loading weight {k} from frozen model")
                del weight
                self.detr.load_state_dict(new_weight)
                del new_weight
            self.detr = DETRsegm(self.detr, freeze_detr=(frozen_weights != ''))
            self.seg_postprocess = PostProcessSegm

        self.detr.to(self.device)

        # building criterion
        matcher = HungarianMatcher(cost_class=1, cost_bbox=l1_weight, cost_giou=giou_weight)
        weight_dict = {"loss_ce": 1, "loss_bbox": l1_weight}
        weight_dict["loss_giou"] = giou_weight
        if deep_supervision:
            aux_weight_dict = {}
            for i in range(dec_layers - 1):
                aux_weight_dict.update({k + f"_{i}": v for k, v in weight_dict.items()})
            weight_dict.update(aux_weight_dict)
        losses = ["labels", "boxes", "cardinality"]
        if self.mask_on:
            losses += ["masks"]
        self.criterion = SetCriterion(
            self.num_classes, matcher=matcher, weight_dict=weight_dict, eos_coef=no_object_weight, losses=losses,
        )
        self.criterion.to(self.device)

        pixel_mean = torch.Tensor(cfg.MODEL.PIXEL_MEAN).to(self.device).view(3, 1, 1)
        pixel_std = torch.Tensor(cfg.MODEL.PIXEL_STD).to(self.device).view(3, 1, 1)
        self.normalizer = lambda x: (x - pixel_mean) / pixel_std
        self.to(self.device)

    def forward(self, batched_inputs):
        """
        Args:
            batched_inputs: a list, batched outputs of :class:`DatasetMapper` .
                Each item in the list contains the inputs for one image.
                For now, each item in the list is a dict that contains:

                * image: Tensor, image in (C, H, W) format.
                * instances: Instances

                Other information that's included in the original dicts, such as:

                * "height", "width" (int): the output resolution of the model, used in inference.
                  See :meth:`postprocess` for details.
        Returns:
            dict[str: Tensor]:
                mapping from a named loss to a tensor storing the loss. Used during training only.
        """
        images = self.preprocess_image(batched_inputs)
        output = self.detr(images)

        if self.training:
            gt_instances = [x["instances"].to(self.device) for x in batched_inputs]

            targets = self.prepare_targets(gt_instances)
            loss_dict = self.criterion(output, targets)
            weight_dict = self.criterion.weight_dict
            for k in loss_dict.keys():
                if k in weight_dict:
                    loss_dict[k] *= weight_dict[k]
            return loss_dict
        else:
            box_cls = output["pred_logits"]
            box_pred = output["pred_boxes"]
            mask_pred = output["pred_masks"] if self.mask_on else None
            results = self.inference(box_cls, box_pred, mask_pred, images.image_sizes)
            processed_results = []
            for results_per_image, input_per_image, image_size in zip(results, batched_inputs, images.image_sizes):
                height = input_per_image.get("height", image_size[0])
                width = input_per_image.get("width", image_size[1])
                r = detector_postprocess(results_per_image, height, width)
                processed_results.append({"instances": r})
            return processed_results

    def prepare_targets(self, targets):
        new_targets = []
        for targets_per_image in targets:
            h, w = targets_per_image.image_size
            image_size_xyxy = torch.as_tensor([w, h, w, h], dtype=torch.float, device=self.device)
            gt_classes = targets_per_image.gt_classes
            gt_boxes = targets_per_image.gt_boxes.tensor / image_size_xyxy
            gt_boxes = box_xyxy_to_cxcywh(gt_boxes)
            new_targets.append({"labels": gt_classes, "boxes": gt_boxes})
            if self.mask_on and hasattr(targets_per_image, 'gt_masks'):
                gt_masks = targets_per_image.gt_masks
                gt_masks = convert_coco_poly_to_mask(gt_masks.polygons, h, w)
                new_targets[-1].update({'masks': gt_masks})
        return new_targets

    def inference(self, box_cls, box_pred, mask_pred, image_sizes):
        """
        Arguments:
            box_cls (Tensor): tensor of shape (batch_size, num_queries, K).
                The tensor predicts the classification probability for each query.
            box_pred (Tensor): tensors of shape (batch_size, num_queries, 4).
                The tensor predicts 4-vector (x,y,w,h) box
                regression values for every queryx
            image_sizes (List[torch.Size]): the input image sizes

        Returns:
            results (List[Instances]): a list of #images elements.
        """
        assert len(box_cls) == len(image_sizes)
        results = []

        # For each box we assign the best class or the second best if the best on is `no_object`.
        scores, labels = F.softmax(box_cls, dim=-1)[:, :, :-1].max(-1)

        for i, (scores_per_image, labels_per_image, box_pred_per_image, image_size) in enumerate(zip(
            scores, labels, box_pred, image_sizes
        )):
            result = Instances(image_size)
            result.pred_boxes = Boxes(box_cxcywh_to_xyxy(box_pred_per_image))

            result.pred_boxes.scale(scale_x=image_size[1], scale_y=image_size[0])
            if self.mask_on:
                mask = F.interpolate(mask_pred[i].unsqueeze(0), size=image_size, mode='bilinear', align_corners=False)
                mask = mask[0].sigmoid() > 0.5
                B, N, H, W = mask_pred.shape
                mask = BitMasks(mask.cpu()).crop_and_resize(result.pred_boxes.tensor.cpu(), 32)
                result.pred_masks = mask.unsqueeze(1).to(mask_pred[0].device)

            result.scores = scores_per_image
            result.pred_classes = labels_per_image
            results.append(result)
        return results

    def preprocess_image(self, batched_inputs):
        """
        Normalize, pad and batch the input images.
        """
        images = [self.normalizer(x["image"].to(self.device)) for x in batched_inputs]
        images = ImageList.from_tensors(images)
        return images



File: d2/detr/config.py

# -*- coding: utf-8 -*-
# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
from detectron2.config import CfgNode as CN


def add_detr_config(cfg):
    """
    Add config for DETR.
    """
    cfg.MODEL.DETR = CN()
    cfg.MODEL.DETR.NUM_CLASSES = 80

    # For Segmentation
    cfg.MODEL.DETR.FROZEN_WEIGHTS = ''

    # LOSS
    cfg.MODEL.DETR.GIOU_WEIGHT = 2.0
    cfg.MODEL.DETR.L1_WEIGHT = 5.0
    cfg.MODEL.DETR.DEEP_SUPERVISION = True
    cfg.MODEL.DETR.NO_OBJECT_WEIGHT = 0.1

    # TRANSFORMER
    cfg.MODEL.DETR.NHEADS = 8
    cfg.MODEL.DETR.DROPOUT = 0.1
    cfg.MODEL.DETR.DIM_FEEDFORWARD = 2048
    cfg.MODEL.DETR.ENC_LAYERS = 6
    cfg.MODEL.DETR.DEC_LAYERS = 6
    cfg.MODEL.DETR.PRE_NORM = False

    cfg.MODEL.DETR.HIDDEN_DIM = 256
    cfg.MODEL.DETR.NUM_OBJECT_QUERIES = 100

    cfg.SOLVER.OPTIMIZER = "ADAMW"
    cfg.SOLVER.BACKBONE_MULTIPLIER = 0.1



File: d2/detr/__init__.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
from .config import add_detr_config
from .detr import Detr
from .dataset_mapper import DetrDatasetMapper



File: d2/detr/dataset_mapper.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
import copy
import logging

import numpy as np
import torch

from detectron2.data import detection_utils as utils
from detectron2.data import transforms as T
from detectron2.data.transforms import TransformGen

__all__ = ["DetrDatasetMapper"]


def build_transform_gen(cfg, is_train):
    """
    Create a list of :class:`TransformGen` from config.
    Returns:
        list[TransformGen]
    """
    if is_train:
        min_size = cfg.INPUT.MIN_SIZE_TRAIN
        max_size = cfg.INPUT.MAX_SIZE_TRAIN
        sample_style = cfg.INPUT.MIN_SIZE_TRAIN_SAMPLING
    else:
        min_size = cfg.INPUT.MIN_SIZE_TEST
        max_size = cfg.INPUT.MAX_SIZE_TEST
        sample_style = "choice"
    if sample_style == "range":
        assert len(min_size) == 2, "more than 2 ({}) min_size(s) are provided for ranges".format(len(min_size))

    logger = logging.getLogger(__name__)
    tfm_gens = []
    if is_train:
        tfm_gens.append(T.RandomFlip())
    tfm_gens.append(T.ResizeShortestEdge(min_size, max_size, sample_style))
    if is_train:
        logger.info("TransformGens used in training: " + str(tfm_gens))
    return tfm_gens


class DetrDatasetMapper:
    """
    A callable which takes a dataset dict in Detectron2 Dataset format,
    and map it into a format used by DETR.

    The callable currently does the following:

    1. Read the image from "file_name"
    2. Applies geometric transforms to the image and annotation
    3. Find and applies suitable cropping to the image and annotation
    4. Prepare image and annotation to Tensors
    """

    def __init__(self, cfg, is_train=True):
        if cfg.INPUT.CROP.ENABLED and is_train:
            self.crop_gen = [
                T.ResizeShortestEdge([400, 500, 600], sample_style="choice"),
                T.RandomCrop(cfg.INPUT.CROP.TYPE, cfg.INPUT.CROP.SIZE),
            ]
        else:
            self.crop_gen = None

        self.mask_on = cfg.MODEL.MASK_ON
        self.tfm_gens = build_transform_gen(cfg, is_train)
        logging.getLogger(__name__).info(
            "Full TransformGens used in training: {}, crop: {}".format(str(self.tfm_gens), str(self.crop_gen))
        )

        self.img_format = cfg.INPUT.FORMAT
        self.is_train = is_train

    def __call__(self, dataset_dict):
        """
        Args:
            dataset_dict (dict): Metadata of one image, in Detectron2 Dataset format.

        Returns:
            dict: a format that builtin models in detectron2 accept
        """
        dataset_dict = copy.deepcopy(dataset_dict)  # it will be modified by code below
        image = utils.read_image(dataset_dict["file_name"], format=self.img_format)
        utils.check_image_size(dataset_dict, image)

        if self.crop_gen is None:
            image, transforms = T.apply_transform_gens(self.tfm_gens, image)
        else:
            if np.random.rand() > 0.5:
                image, transforms = T.apply_transform_gens(self.tfm_gens, image)
            else:
                image, transforms = T.apply_transform_gens(
                    self.tfm_gens[:-1] + self.crop_gen + self.tfm_gens[-1:], image
                )

        image_shape = image.shape[:2]  # h, w

        # Pytorch's dataloader is efficient on torch.Tensor due to shared-memory,
        # but not efficient on large generic data structures due to the use of pickle & mp.Queue.
        # Therefore it's important to use torch.Tensor.
        dataset_dict["image"] = torch.as_tensor(np.ascontiguousarray(image.transpose(2, 0, 1)))

        if not self.is_train:
            # USER: Modify this if you want to keep them for some reason.
            dataset_dict.pop("annotations", None)
            return dataset_dict

        if "annotations" in dataset_dict:
            # USER: Modify this if you want to keep them for some reason.
            for anno in dataset_dict["annotations"]:
                if not self.mask_on:
                    anno.pop("segmentation", None)
                anno.pop("keypoints", None)

            # USER: Implement additional transformations if you have other types of data
            annos = [
                utils.transform_instance_annotations(obj, transforms, image_shape)
                for obj in dataset_dict.pop("annotations")
                if obj.get("iscrowd", 0) == 0
            ]
            instances = utils.annotations_to_instances(annos, image_shape)
            dataset_dict["instances"] = utils.filter_empty_instances(instances)
        return dataset_dict



**DE⫶TR**: End-to-End Object Detection with Transformers
========

[![Support Ukraine](https://img.shields.io/badge/Support-Ukraine-FFD500?style=flat&labelColor=005BBB)](https://opensource.fb.com/support-ukraine)

PyTorch training code and pretrained models for **DETR** (**DE**tection **TR**ansformer).
We replace the full complex hand-crafted object detection pipeline with a Transformer, and match Faster R-CNN with a ResNet-50, obtaining **42 AP** on COCO using half the computation power (FLOPs) and the same number of parameters. Inference in 50 lines of PyTorch.

![DETR](.github/DETR.png)

**What it is**. Unlike traditional computer vision techniques, DETR approaches object detection as a direct set prediction problem. It consists of a set-based global loss, which forces unique predictions via bipartite matching, and a Transformer encoder-decoder architecture. 
Given a fixed small set of learned object queries, DETR reasons about the relations of the objects and the global image context to directly output the final set of predictions in parallel. Due to this parallel nature, DETR is very fast and efficient.

**About the code**. We believe that object detection should not be more difficult than classification,
and should not require complex libraries for training and inference.
DETR is very simple to implement and experiment with, and we provide a
[standalone Colab Notebook](https://colab.research.google.com/github/facebookresearch/detr/blob/colab/notebooks/detr_demo.ipynb)
showing how to do inference with DETR in only a few lines of PyTorch code.
Training code follows this idea - it is not a library,
but simply a [main.py](main.py) importing model and criterion
definitions with standard training loops.

Additionnally, we provide a Detectron2 wrapper in the d2/ folder. See the readme there for more information.

For details see [End-to-End Object Detection with Transformers](https://ai.facebook.com/research/publications/end-to-end-object-detection-with-transformers) by Nicolas Carion, Francisco Massa, Gabriel Synnaeve, Nicolas Usunier, Alexander Kirillov, and Sergey Zagoruyko.

See our [blog post](https://ai.facebook.com/blog/end-to-end-object-detection-with-transformers/) to learn more about end to end object detection with transformers.
# Model Zoo
We provide baseline DETR and DETR-DC5 models, and plan to include more in future.
AP is computed on COCO 2017 val5k, and inference time is over the first 100 val5k COCO images,
with torchscript transformer.

<table>
  <thead>
    <tr style="text-align: right;">
      <th></th>
      <th>name</th>
      <th>backbone</th>
      <th>schedule</th>
      <th>inf_time</th>
      <th>box AP</th>
      <th>url</th>
      <th>size</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <th>0</th>
      <td>DETR</td>
      <td>R50</td>
      <td>500</td>
      <td>0.036</td>
      <td>42.0</td>
      <td><a href="https://dl.fbaipublicfiles.com/detr/detr-r50-e632da11.pth">model</a>&nbsp;|&nbsp;<a href="https://dl.fbaipublicfiles.com/detr/logs/detr-r50_log.txt">logs</a></td>
      <td>159Mb</td>
    </tr>
    <tr>
      <th>1</th>
      <td>DETR-DC5</td>
      <td>R50</td>
      <td>500</td>
      <td>0.083</td>
      <td>43.3</td>
      <td><a href="https://dl.fbaipublicfiles.com/detr/detr-r50-dc5-f0fb7ef5.pth">model</a>&nbsp;|&nbsp;<a href="https://dl.fbaipublicfiles.com/detr/logs/detr-r50-dc5_log.txt">logs</a></td>
      <td>159Mb</td>
    </tr>
    <tr>
      <th>2</th>
      <td>DETR</td>
      <td>R101</td>
      <td>500</td>
      <td>0.050</td>
      <td>43.5</td>
      <td><a href="https://dl.fbaipublicfiles.com/detr/detr-r101-2c7b67e5.pth">model</a>&nbsp;|&nbsp;<a href="https://dl.fbaipublicfiles.com/detr/logs/detr-r101_log.txt">logs</a></td>
      <td>232Mb</td>
    </tr>
    <tr>
      <th>3</th>
      <td>DETR-DC5</td>
      <td>R101</td>
      <td>500</td>
      <td>0.097</td>
      <td>44.9</td>
      <td><a href="https://dl.fbaipublicfiles.com/detr/detr-r101-dc5-a2e86def.pth">model</a>&nbsp;|&nbsp;<a href="https://dl.fbaipublicfiles.com/detr/logs/detr-r101-dc5_log.txt">logs</a></td>
      <td>232Mb</td>
    </tr>
  </tbody>
</table>

COCO val5k evaluation results can be found in this [gist](https://gist.github.com/szagoruyko/9c9ebb8455610958f7deaa27845d7918).

The models are also available via torch hub,
to load DETR R50 with pretrained weights simply do:
```python
model = torch.hub.load('facebookresearch/detr:main', 'detr_resnet50', pretrained=True)
```


COCO panoptic val5k models:
<table>
  <thead>
    <tr style="text-align: right;">
      <th></th>
      <th>name</th>
      <th>backbone</th>
      <th>box AP</th>
      <th>segm AP</th>
      <th>PQ</th>
      <th>url</th>
      <th>size</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <th>0</th>
      <td>DETR</td>
      <td>R50</td>
      <td>38.8</td>
      <td>31.1</td>
      <td>43.4</td>
      <td><a href="https://dl.fbaipublicfiles.com/detr/detr-r50-panoptic-00ce5173.pth">download</a></td>
      <td>165Mb</td>
    </tr>
    <tr>
      <th>1</th>
      <td>DETR-DC5</td>
      <td>R50</td>
      <td>40.2</td>
      <td>31.9</td>
      <td>44.6</td>
      <td><a href="https://dl.fbaipublicfiles.com/detr/detr-r50-dc5-panoptic-da08f1b1.pth">download</a></td>
      <td>165Mb</td>
    </tr>
    <tr>
      <th>2</th>
      <td>DETR</td>
      <td>R101</td>
      <td>40.1</td>
      <td>33</td>
      <td>45.1</td>
      <td><a href="https://dl.fbaipublicfiles.com/detr/detr-r101-panoptic-40021d53.pth">download</a></td>
      <td>237Mb</td>
    </tr>
  </tbody>
</table>

Checkout our [panoptic colab](https://colab.research.google.com/github/facebookresearch/detr/blob/colab/notebooks/DETR_panoptic.ipynb)
to see how to use and visualize DETR's panoptic segmentation prediction.

# Notebooks

We provide a few notebooks in colab to help you get a grasp on DETR:
* [DETR's hands on Colab Notebook](https://colab.research.google.com/github/facebookresearch/detr/blob/colab/notebooks/detr_attention.ipynb): Shows how to load a model from hub, generate predictions, then visualize the attention of the model (similar to the figures of the paper)
* [Standalone Colab Notebook](https://colab.research.google.com/github/facebookresearch/detr/blob/colab/notebooks/detr_demo.ipynb): In this notebook, we demonstrate how to implement a simplified version of DETR from the grounds up in 50 lines of Python, then visualize the predictions. It is a good starting point if you want to gain better understanding the architecture and poke around before diving in the codebase.
* [Panoptic Colab Notebook](https://colab.research.google.com/github/facebookresearch/detr/blob/colab/notebooks/DETR_panoptic.ipynb): Demonstrates how to use DETR for panoptic segmentation and plot the predictions.


# Usage - Object detection
There are no extra compiled components in DETR and package dependencies are minimal,
so the code is very simple to use. We provide instructions how to install dependencies via conda.
First, clone the repository locally:
```
git clone https://github.com/facebookresearch/detr.git
```
Then, install PyTorch 1.5+ and torchvision 0.6+:
```
conda install -c pytorch pytorch torchvision
```
Install pycocotools (for evaluation on COCO) and scipy (for training):
```
conda install cython scipy
pip install -U 'git+https://github.com/cocodataset/cocoapi.git#subdirectory=PythonAPI'
```
That's it, should be good to train and evaluate detection models.

(optional) to work with panoptic install panopticapi:
```
pip install git+https://github.com/cocodataset/panopticapi.git
```

## Data preparation

Download and extract COCO 2017 train and val images with annotations from
[http://cocodataset.org](http://cocodataset.org/#download).
We expect the directory structure to be the following:
```
path/to/coco/
  annotations/  # annotation json files
  train2017/    # train images
  val2017/      # val images
```

## Training
To train baseline DETR on a single node with 8 gpus for 300 epochs run:
```
python -m torch.distributed.launch --nproc_per_node=8 --use_env main.py --coco_path /path/to/coco 
```
A single epoch takes 28 minutes, so 300 epoch training
takes around 6 days on a single machine with 8 V100 cards.
To ease reproduction of our results we provide
[results and training logs](https://gist.github.com/szagoruyko/b4c3b2c3627294fc369b899987385a3f)
for 150 epoch schedule (3 days on a single machine), achieving 39.5/60.3 AP/AP50.

We train DETR with AdamW setting learning rate in the transformer to 1e-4 and 1e-5 in the backbone.
Horizontal flips, scales and crops are used for augmentation.
Images are rescaled to have min size 800 and max size 1333.
The transformer is trained with dropout of 0.1, and the whole model is trained with grad clip of 0.1.


## Evaluation
To evaluate DETR R50 on COCO val5k with a single GPU run:
```
python main.py --batch_size 2 --no_aux_loss --eval --resume https://dl.fbaipublicfiles.com/detr/detr-r50-e632da11.pth --coco_path /path/to/coco
```
We provide results for all DETR detection models in this
[gist](https://gist.github.com/szagoruyko/9c9ebb8455610958f7deaa27845d7918).
Note that numbers vary depending on batch size (number of images) per GPU.
Non-DC5 models were trained with batch size 2, and DC5 with 1,
so DC5 models show a significant drop in AP if evaluated with more
than 1 image per GPU.

## Multinode training
Distributed training is available via Slurm and [submitit](https://github.com/facebookincubator/submitit):
```
pip install submitit
```
Train baseline DETR-6-6 model on 4 nodes for 300 epochs:
```
python run_with_submitit.py --timeout 3000 --coco_path /path/to/coco
```

# Usage - Segmentation

We show that it is relatively straightforward to extend DETR to predict segmentation masks. We mainly demonstrate strong panoptic segmentation results.

## Data preparation

For panoptic segmentation, you need the panoptic annotations additionally to the coco dataset (see above for the coco dataset). You need to download and extract the [annotations](http://images.cocodataset.org/annotations/panoptic_annotations_trainval2017.zip).
We expect the directory structure to be the following:
```
path/to/coco_panoptic/
  annotations/  # annotation json files
  panoptic_train2017/    # train panoptic annotations
  panoptic_val2017/      # val panoptic annotations
```

## Training

We recommend training segmentation in two stages: first train DETR to detect all the boxes, and then train the segmentation head.
For panoptic segmentation, DETR must learn to detect boxes for both stuff and things classes. You can train it on a single node with 8 gpus for 300 epochs with:
```
python -m torch.distributed.launch --nproc_per_node=8 --use_env main.py --coco_path /path/to/coco  --coco_panoptic_path /path/to/coco_panoptic --dataset_file coco_panoptic --output_dir /output/path/box_model
```
For instance segmentation, you can simply train a normal box model (or used a pre-trained one we provide).

Once you have a box model checkpoint, you need to freeze it, and train the segmentation head in isolation.
For panoptic segmentation you can train on a single node with 8 gpus for 25 epochs:
```
python -m torch.distributed.launch --nproc_per_node=8 --use_env main.py --masks --epochs 25 --lr_drop 15 --coco_path /path/to/coco  --coco_panoptic_path /path/to/coco_panoptic  --dataset_file coco_panoptic --frozen_weights /output/path/box_model/checkpoint.pth --output_dir /output/path/segm_model
```
For instance segmentation only, simply remove the `dataset_file` and `coco_panoptic_path` arguments from the above command line.

# License
DETR is released under the Apache 2.0 license. Please see the [LICENSE](LICENSE) file for more information.

# Contributing
We actively welcome your pull requests! Please see [CONTRIBUTING.md](.github/CONTRIBUTING.md) and [CODE_OF_CONDUCT.md](.github/CODE_OF_CONDUCT.md) for more info.
