Add workspace scale control to avoid in-canvas zoom draw lag

app.py

@@ -1346,11 +1346,27 @@ def load_image(file_path, page_num=1):
     else:
         return Image.open(file_path)
 
-def load_image_with_size(file_path, page_num=1):
+def _scale_workspace_image(img, workspace_scale):
+    if img is None:
+        return None
+    try:
+        scale = max(100, min(220, int(workspace_scale)))
+    except Exception:
+        scale = 100
+    if scale == 100:
+        return img
+    ratio = scale / 100.0
+    new_w = max(1, int(round(img.width * ratio)))
+    new_h = max(1, int(round(img.height * ratio)))
+    resample = Image.Resampling.BILINEAR if hasattr(Image, "Resampling") else Image.BILINEAR
+    return img.resize((new_w, new_h), resample)
+
+def load_image_with_size(file_path, page_num=1, workspace_scale=100):
     img = load_image(file_path, page_num)
     if img is None:
         return None, None, None
-    return img, (int(img.width), int(img.height)), img
+    display_img = _scale_workspace_image(img, workspace_scale)
+    return display_img, (int(display_img.width), int(display_img.height)), display_img
 
 def sync_workspace_state(editor_value, current_base_image):
     background = _extract_editor_background(editor_value)
@@ -1467,6 +1483,14 @@ with gr.Blocks(**blocks_kwargs) as demo:
             gr.Markdown("### OCR Workflow")
             task = gr.Dropdown(list(TASK_PROMPTS.keys()), value="📋 Markdown", label="Task")
             input_scope = gr.Radio(["Entire Page", "Selected Region"], value="Entire Page", label="Input Scope")
+            workspace_scale = gr.Slider(
+                minimum=100,
+                maximum=220,
+                step=10,
+                value=140,
+                label="Workspace Scale (%)",
+                info="Use this instead of in-canvas zoom for smoother live drawing.",
+            )
 
             selection_controls = gr.Row(visible=False)
             with selection_controls:
@@ -1543,6 +1567,7 @@ with gr.Blocks(**blocks_kwargs) as demo:
         2. Choose **Input Scope**:
            - `Entire Page` for the full page.
            - `Selected Region` for a specific area.
+        2a. For small math, increase **Workspace Scale** instead of using in-canvas zoom (better live drawing feedback).
         3. For `Selected Region`, use the **Image Workspace**:
            - Recommended: freehand selection (draw/highlight target); app uses an automatic bounding box around your marks.
            - Optional rectangle selection: use the **Crop** tool.
@@ -1583,13 +1608,16 @@ with gr.Blocks(**blocks_kwargs) as demo:
     task.change(select_boxes, [task], [tabs])
     input_scope.change(toggle_scope_ui, [input_scope], [workspace_hint, selection_controls, selection_status, selected_regions_gallery])
     if HAS_REGION_WORKSPACE and region_editor is not None:
-        file_in.change(load_image_with_size, [file_in, page_selector], [region_editor, workspace_base_size, workspace_base_image])
-        page_selector.change(load_image_with_size, [file_in, page_selector], [region_editor, workspace_base_size, workspace_base_image])
+        file_in.change(load_image_with_size, [file_in, page_selector, workspace_scale], [region_editor, workspace_base_size, workspace_base_image])
+        page_selector.change(load_image_with_size, [file_in, page_selector, workspace_scale], [region_editor, workspace_base_size, workspace_base_image])
+        workspace_scale.change(load_image_with_size, [file_in, page_selector, workspace_scale], [region_editor, workspace_base_size, workspace_base_image])
         region_editor.change(sync_workspace_state, [region_editor, workspace_base_image], [workspace_base_size, workspace_base_image])
         file_in.change(_reset_selected_regions, outputs=[selected_regions_state, selected_regions_gallery, selection_status])
         page_selector.change(_reset_selected_regions, outputs=[selected_regions_state, selected_regions_gallery, selection_status])
+        workspace_scale.change(_reset_selected_regions, outputs=[selected_regions_state, selected_regions_gallery, selection_status])
         file_in.change(_reset_drawn_mask, outputs=[drawn_mask_state])
         page_selector.change(_reset_drawn_mask, outputs=[drawn_mask_state])
+        workspace_scale.change(_reset_drawn_mask, outputs=[drawn_mask_state])
 
     add_region_btn.click(
         add_selected_region,
@@ -1643,20 +1671,20 @@ with gr.Blocks(**blocks_kwargs) as demo:
             full_img = base_image if isinstance(base_image, Image.Image) else _extract_editor_background(region_value)
             region_boxes = [r["bbox"] for r in regions if r.get("bbox") is not None]
             img_out = _draw_selected_region_boxes(full_img, region_boxes)
-        elif (full_image := _extract_editor_background(region_value)) is not None:
-            cleaned, markdown, raw, img_out, crops = process_image(
-                full_image,
+        elif file_path:
+            cleaned, markdown, raw, img_out, crops = process_file(
+                file_path,
                 task,
                 custom_prompt,
+                int(page_num),
                 enable_equation_zoom=enable_equation_zoom,
                 separate_equation_lines=detect_eq_lines,
             )
-        elif file_path:
-            cleaned, markdown, raw, img_out, crops = process_file(
-                file_path,
+        elif (full_image := _extract_editor_background(region_value)) is not None:
+            cleaned, markdown, raw, img_out, crops = process_image(
+                full_image,
                 task,
                 custom_prompt,
-                int(page_num),
                 enable_equation_zoom=enable_equation_zoom,
                 separate_equation_lines=detect_eq_lines,
             )