fix edge tiles

inference_tab/helpers.py

@@ -374,10 +374,12 @@ def merge_tile_masks(H, W):
                 mask = np.pad(mask, ((0, pad_h), (0, pad_w)), mode='constant', constant_values=0)
 
 
-            h_end = y_off + mask.shape[0]
-            w_end = x_off + mask.shape[1]
+            h_end = min(y_off + mask.shape[0], H)
+            w_end = min(x_off + mask.shape[1], W)
+
             region = full_mask[y_off:h_end, x_off:w_end]
-            
+            mask   = mask[:h_end - y_off, :w_end - x_off]
+
             region[mask & (region == 0)] = instance_id
             instance_id += 1