Update app.py

app.py

@@ -16,6 +16,10 @@ logger = logging.getLogger(__name__)
 def stitch_images_vertically(images: List[Image.Image]) -> Image.Image:
     if not images:
         return None
+    
+    if not all(isinstance(i, Image.Image) for i in images):
+        logger.error("Non-Image object found in list for vertical stitching.")
+        return None
 
     max_width = max(img.width for img in images)
     total_height = sum(img.height for img in images)
@@ -33,11 +37,13 @@ def stitch_images_in_grid(images: List[Image.Image], num_columns: int) -> Image.
     if not images:
         return None
 
-    num_images = len(images)
     columns = [images[i::num_columns] for i in range(num_columns)]
     
-    stitched_columns = [stitch_images_vertically(col) for col in columns]
+    stitched_columns = [stitch_images_vertically(col) for col in columns if col]
     
+    if not stitched_columns:
+        return None
+        
     max_height = max(col.height for col in stitched_columns if col)
     total_width = sum(col.width for col in stitched_columns if col)
     
@@ -51,7 +57,7 @@ def stitch_images_in_grid(images: List[Image.Image], num_columns: int) -> Image.
             
     return grid_image
 
-def process_pdf(pdf_file, pdf_url, dpi, num_columns, progress=gr.Progress()):
+def process_pdf(pdf_file, pdf_url, dpi, num_columns, crop_top, crop_bottom, crop_left, crop_right, progress=gr.Progress()):
     pdf_input_source = None
     is_bytes = False
     source_name = "document"
@@ -93,12 +99,30 @@ def process_pdf(pdf_file, pdf_url, dpi, num_columns, progress=gr.Progress()):
     
     logger.info(f"Successfully converted {len(images)} pages to images.")
 
-    progress(0.7, desc=f"Stitching {len(images)} images together...")
+    cropped_images = []
+    if crop_top > 0 or crop_bottom > 0 or crop_left > 0 or crop_right > 0:
+        progress(0.6, desc="Cropping images...")
+        for i, img in enumerate(images):
+            width, height = img.size
+            
+            left = crop_left
+            top = crop_top
+            right = width - crop_right
+            bottom = height - crop_bottom
+
+            if left >= right or top >= bottom:
+                raise gr.Error(f"Crop values are too large for page {i+1}. The page dimensions are {width}x{height}, but crop settings result in an invalid area.")
+            
+            cropped_images.append(img.crop((left, top, right, bottom)))
+    else:
+        cropped_images = images
+
+    progress(0.7, desc=f"Stitching {len(cropped_images)} images together...")
     
     if num_columns > 1:
-        stitched_image = stitch_images_in_grid(images, num_columns)
+        stitched_image = stitch_images_in_grid(cropped_images, num_columns)
     else:
-        stitched_image = stitch_images_vertically(images)
+        stitched_image = stitch_images_vertically(cropped_images)
         
     if stitched_image is None:
         raise gr.Error("Image stitching failed.")
@@ -136,42 +160,36 @@ with gr.Blocks(theme=gr.themes.Soft()) as demo:
                         placeholder="e.g., https://arxiv.org/pdf/1706.03762.pdf"
                     )
             
-            dpi_slider = gr.Slider(
-                minimum=100,
-                maximum=600,
-                step=10,
-                value=200,
-                label="Image Resolution (DPI)",
-                info="Higher DPI results in a clearer image but increases processing time and file size."
-            )
-
-            columns_slider = gr.Slider(
-                minimum=1,
-                maximum=10,
-                step=1,
-                value=1,
-                label="Number of Columns",
-                info="Increase to make the final image wider and less tall."
-            )
+            dpi_slider = gr.Slider(minimum=100, maximum=600, step=50, value=200, label="Image Resolution (DPI)")
+            columns_slider = gr.Slider(minimum=1, maximum=10, step=1, value=1, label="Number of Columns")
+
+            with gr.Accordion("Advanced Options", open=False):
+                with gr.Row():
+                    crop_left = gr.Slider(minimum=0, maximum=500, step=10, value=0, label="Crop Left")
+                    crop_right = gr.Slider(minimum=0, maximum=500, step=10, value=0, label="Crop Right")
+                with gr.Row():
+                    crop_top = gr.Slider(minimum=0, maximum=500, step=10, value=0, label="Crop Top")
+                    crop_bottom = gr.Slider(minimum=0, maximum=500, step=10, value=0, label="Crop Bottom")
             
             submit_btn = gr.Button("Stitch PDF Pages", variant="primary")
 
         with gr.Column(scale=2):
             gr.Markdown("## Output")
-            output_image_preview = gr.Image(
-                label="Stitched Image Preview",
-                type="filepath",
-                interactive=False,
-                height=600,
-            )
-            output_image_download = gr.File(
-                label="Download Stitched Image",
-                interactive=False
-            )
+            output_image_preview = gr.Image(label="Stitched Image Preview", type="filepath", interactive=False, height=600)
+            output_image_download = gr.File(label="Download Stitched Image", interactive=False)
 
     submit_btn.click(
         fn=process_pdf,
-        inputs=[pdf_file_input, pdf_url_input, dpi_slider, columns_slider],
+        inputs=[
+            pdf_file_input, 
+            pdf_url_input, 
+            dpi_slider, 
+            columns_slider, 
+            crop_top, 
+            crop_bottom, 
+            crop_left, 
+            crop_right
+        ],
         outputs=[output_image_preview, output_image_download]
     )