app.py

import subprocess  # 🥲

subprocess.run(
    "pip install flash-attn --no-build-isolation",
    env={"FLASH_ATTENTION_SKIP_CUDA_BUILD": "TRUE"},
    shell=True,
)
import spaces
import gradio as gr

from transformers import Qwen2VLForConditionalGeneration, AutoProcessor
from qwen_vl_utils import process_vision_info
import torch
import os
import json
from pydantic import BaseModel
from typing import Tuple

os.environ["HF_HUB_ENABLE_HF_TRANSFER"] = "1"


model = Qwen2VLForConditionalGeneration.from_pretrained(
    "Qwen/Qwen2-VL-7B-Instruct",
    torch_dtype=torch.bfloat16,
    attn_implementation="flash_attention_2",
    device_map="auto",
)
processor = AutoProcessor.from_pretrained("Qwen/Qwen2-VL-7B-Instruct")


class GeneralRetrievalQuery(BaseModel):
    broad_topical_query: str
    broad_topical_explanation: str
    specific_detail_query: str
    specific_detail_explanation: str
    visual_element_query: str
    visual_element_explanation: str


def get_retrieval_prompt(prompt_name: str) -> Tuple[str, BaseModel]:
    if prompt_name == "general":
        prompt = """You are an AI assistant specialized in document retrieval tasks. Given an image of a document page, your task is to generate retrieval queries that someone might use to find this document in a large corpus.

Please generate 3 different types of retrieval queries:

1. A broad topical query: This should cover the main subject of the document.
2. A specific detail query: This should focus on a particular fact, figure, or point made in the document.
3. A visual element query: This should reference a chart, graph, image, or other visual component in the document, if present.

Important guidelines:
- Ensure the queries are relevant for retrieval tasks, not just describing the page content.
- Frame the queries as if someone is searching for this document, not asking questions about its content.
- Make the queries diverse and representative of different search strategies.

For each query, also provide a brief explanation of why this query would be effective in retrieving this document.

Format your response as a JSON object with the following structure:

{
  "broad_topical_query": "Your query here",
  "broad_topical_explanation": "Brief explanation",
  "specific_detail_query": "Your query here",
  "specific_detail_explanation": "Brief explanation",
  "visual_element_query": "Your query here",
  "visual_element_explanation": "Brief explanation"
}

If there are no relevant visual elements, replace the third query with another specific detail query.

Here is the document image to analyze:
<image>

Generate the queries based on this image and provide the response in the specified JSON format."""
        return prompt, GeneralRetrievalQuery
    elif prompt_name == "multimodal_rag":
        prompt = """You are an assistant specialized in Multimodal RAG tasks.

The task is the following: given an image from a pdf page, you will have to generate questions that can be asked by a user to retrieve information from a large documentary corpus.

The question should be relevant to the page, and should not be too specific or too general. The question should be about the subject of the page, and the answer needs to be found in the page.

Remember that the question is asked by a user to get some information from a large documentary corpus that contains multimodal data. Generate a question that could be asked by a user without knowing the existence and the content of the corpus.

Generate as well the answer to the question, which should be found in the page. And the format of the answer should be a list of words answering the question.

Generate at most THREE pairs of questions and answers per page as JSON with the following format, answer ONLY using JSON, NOTHING ELSE:

{
"questions": [
{
"question": "XXXXXX",
"answer": ["YYYYYY"]
},
{
"question": "XXXXXX",
"answer": ["YYYYYY"]
},
{
"question": "XXXXXX",
"answer": ["YYYYYY"]
}
]
}

where XXXXXX is the question and ['YYYYYY'] is the corresponding list of answers that could be as long as needed.

Note: If there are no questions to ask about the page, return an empty list. Focus on making relevant questions concerning the page.

Here is the page:"""
        return prompt, BaseModel
    else:
        raise ValueError("Invalid prompt name")


# defined like this so we can later add more prompting options
prompt, pydantic_model = get_retrieval_prompt("general")


def _prep_data_for_input(image, prompt):
    messages = [
        {
            "role": "user",
            "content": [
                {
                    "type": "image",
                    "image": image,
                },
                {"type": "text", "text": prompt},
            ],
        }
    ]

    text = processor.apply_chat_template(
        messages, tokenize=False, add_generation_prompt=True
    )

    image_inputs, video_inputs = process_vision_info(messages)

    return processor(
        text=[text],
        images=image_inputs,
        videos=video_inputs,
        padding=True,
        return_tensors="pt",
    )


@spaces.GPU
def generate_response(image, prompt_name="general"):
    prompt, _ = get_retrieval_prompt(prompt_name)
    inputs = _prep_data_for_input(image, prompt)
    inputs.to("cuda")
    generated_ids = model.generate(**inputs, max_new_tokens=200)
    generated_ids_trimmed = [
        out_ids[len(in_ids) :]
        for in_ids, out_ids in zip(inputs.input_ids, generated_ids)
    ]

    output_text = processor.batch_decode(
        generated_ids_trimmed,
        skip_special_tokens=True,
        clean_up_tokenization_spaces=False,
    )
    try:
        return json.loads(output_text[0])
    except Exception:
        gr.Warning("Failed to parse JSON from output")
        return {}


title = "ColPali fine-tuning Query Generator"
description = """[ColPali](https://huggingface.co/papers/2407.01449) is a very exciting new approach to multimodal document retrieval which aims to replace existing document retrievers which often rely on an OCR step with an end-to-end multimodal approach. 

To train or fine-tune a ColPali model, we need a dataset of image-text pairs which represent the document images and the relevant text queries which those documents should match. 
To make the ColPali models work even better we might want a dataset of query/image document pairs related to our domain or task. 

One way in which we might go about generating such a dataset is to use an VLM to generate synthetic queries for us. 
This space uses the [Qwen/Qwen2-VL-7B-Instruct](https://huggingface.co/Qwen/Qwen2-VL-7B-Instruct) VLM model to generate queries for a document, based on an input document image. 


This [blog post](https://danielvanstrien.xyz/posts/post-with-code/colpali/2024-09-23-generate_colpali_dataset.html) gives an overview of how you can use this kind of approach to generate a full dataset for fine-tuning ColPali models. 

If you want to convert a PDF(s) to a dataset of page images you can try out the [ PDFs to Page Images Converter](https://huggingface.co/spaces/Dataset-Creation-Tools/pdf-to-page-images-dataset) Space.

"""

examples = [
    "examples/Approche_no_13_1977.pdf_page_22.jpg",
    "examples/SRCCL_Technical-Summary.pdf_page_7.jpg",
]

demo = gr.Interface(
    fn=generate_response,
    inputs=[
        gr.Image(type="pil"),
        gr.Dropdown(
            choices=["ColPali paper prompt", "retrieval focused prompt"],
            value="general",
            label="Prompt Type",
        ),
    ],
    outputs=gr.Json(),
    title=title,
    description=description,
    examples=examples,
)
demo.launch()