Update app.py

app.py

@@ -46,17 +46,37 @@ def parse_xml_points(xml_file):
     return np.array(points,dtype=np.float32).reshape(-1,2)
 
 # ---------------- Padding Helper ----------------
-def pad_to_size(img, target_h, target_w):
+def pad_to_match(img, target_h=None, target_w=None):
     h, w = img.shape[:2]
-    top_pad = 0
-    left_pad = 0
-    bottom_pad = target_h - h
-    right_pad = target_w - w
-    # Create white canvas
-    canvas = np.ones((target_h, target_w,3), dtype=np.uint8)*255
-    canvas[top_pad:top_pad+h, left_pad:left_pad+w] = img
+    pad_top, pad_bottom, pad_left, pad_right = 0,0,0,0
+    if target_h is not None and h < target_h:
+        diff = target_h - h
+        pad_top = diff // 2
+        pad_bottom = diff - pad_top
+    if target_w is not None and w < target_w:
+        diff = target_w - w
+        pad_left = diff // 2
+        pad_right = diff - pad_left
+    canvas = np.ones((h+pad_top+pad_bottom, w+pad_left+pad_right,3), dtype=np.uint8)*255
+    canvas[pad_top:pad_top+h, pad_left:pad_left+w] = img
     return canvas
 
+def merge_2x2_grid(images):
+    top_h = max(images[0].shape[0], images[1].shape[0])
+    bottom_h = max(images[2].shape[0], images[3].shape[0])
+    left_w = max(images[0].shape[1], images[2].shape[1])
+    right_w = max(images[1].shape[1], images[3].shape[1])
+
+    flat_pad  = pad_to_match(images[0], target_h=top_h, target_w=left_w)
+    match_pad = pad_to_match(images[1], target_h=top_h, target_w=right_w)
+    roi_pad   = pad_to_match(images[2], target_h=bottom_h, target_w=left_w)
+    xml_pad   = pad_to_match(images[3], target_h=bottom_h, target_w=right_w)
+
+    top_row = np.hstack([flat_pad, match_pad])
+    bottom_row = np.hstack([roi_pad, xml_pad])
+    grid = np.vstack([top_row, bottom_row])
+    return grid
+
 # ---------------- Main Function ----------------
 def homography_all_detectors(flat_file, persp_file, json_file, xml_file):
     flat_img = cv2.imread(flat_file)
@@ -102,22 +122,8 @@ def homography_all_detectors(flat_file, persp_file, json_file, xml_file):
         roi_rgb = cv2.cvtColor(persp_roi,cv2.COLOR_BGR2RGB)
         xml_rgb = cv2.cvtColor(xml_gt_img,cv2.COLOR_BGR2RGB)
 
-        # Determine max height and width for padding
-        max_h = max(flat_rgb.shape[0], match_rgb.shape[0], roi_rgb.shape[0], xml_rgb.shape[0])
-        max_w = max(flat_rgb.shape[1], match_rgb.shape[1], roi_rgb.shape[1], xml_rgb.shape[1])
-
-        # Pad all images to same size
-        flat_pad = pad_to_size(flat_rgb, max_h, max_w)
-        match_pad = pad_to_size(match_rgb, max_h, max_w)
-        roi_pad = pad_to_size(roi_rgb, max_h, max_w)
-        xml_pad = pad_to_size(xml_rgb, max_h, max_w)
-
-        # Merge 2x2 grid
-        top = np.hstack([flat_pad, match_pad])
-        bottom = np.hstack([roi_pad, xml_pad])
-        combined_grid = np.vstack([top, bottom])
+        combined_grid = merge_2x2_grid([flat_rgb, match_rgb, roi_rgb, xml_rgb])
 
-        # Save combined grid
         base_name = os.path.splitext(os.path.basename(persp_file))[0]
         file_name = f"{base_name}_{method.lower()}.png"
         cv2.imwrite(file_name, cv2.cvtColor(combined_grid,cv2.COLOR_RGB2BGR))