Update app.py

app.py

@@ -409,8 +409,8 @@ def apply_mask(d, b):
     mask = cv2.inRange(d["background"], np.array([255,255,255,255]), np.array([255,255,255,255]))
 
     for k, mk in enumerate(masks):
-        if k != frame_selected:
-            masks[k] = cv2.imread(f"f{k}_dmap.png").astype(np.uint8)
+        if k != frame_selected and k < len(depths):
+            masks[k] = cv2.imread(depths[k]).astype(np.uint8)
             masks[k][dmask==0] = (255,255,255)
 
     masks[frame_selected] = d["background"]