Update app.py

app.py

@@ -27,9 +27,14 @@ def warp_design(design, mask, warp_scale):
     """Warp the design using TPS and scale control."""
     h, w = mask.shape[:2]
     design_resized = cv2.resize(design, (w, h))
-    
-    # Apply scaling
+
+    # Ensure mask is in correct format
     scaled_mask = (mask * 255 * (warp_scale / 100)).astype(np.uint8)
+    
+    # Ensure mask is single-channel
+    if len(scaled_mask.shape) == 3:
+        scaled_mask = cv2.cvtColor(scaled_mask, cv2.COLOR_BGR2GRAY)
+
     return cv2.bitwise_and(design_resized, design_resized, mask=scaled_mask)
 
 def blend_images(base, overlay, mask):