fix: correct invert_mask logic - RGB masks already have white=remove, only invert if invert_mask=False explicitly requested

src/core.py

@@ -490,18 +490,23 @@ def process_inpaint(image, mask, invert_mask=True):
         mask = 255 - alpha_channel
         transparent_count = int((alpha_channel < 128).sum())
         print(f"Using alpha channel: {transparent_count} transparent pixels → white (to remove)")
+        # For alpha-based masks: invert_mask=True means keep current (white=remove is correct)
+        # invert_mask=False means invert (white becomes black)
+        if not invert_mask:
+            mask = 255 - mask
+            print(f"Applied invert_mask=False: inverted alpha-based mask")
     else:
         # Alpha is mostly opaque (255), use RGB channels instead
-        # RGB masks: white (255) = remove, black (0) = keep
+        # RGB masks: white (255) = remove, black (0) = keep (standard convention)
         gray = cv2.cvtColor(rgb_channels, cv2.COLOR_RGB2GRAY)
         mask = (gray > 128).astype(np.uint8) * 255
         white_count = int((mask > 128).sum())
         print(f"Using RGB channels: {white_count} white pixels (to remove)")
-    
-    # Apply invert_mask if user wants opposite behavior
-    if not invert_mask:
-        mask = 255 - mask  # invert: white becomes black, black becomes white
-        print(f"Applied invert_mask=False: inverted mask")
+        # For RGB-based masks: white=remove is already correct
+        # invert_mask=False means we want black=remove (invert it)
+        if not invert_mask:
+            mask = 255 - mask  # invert: white becomes black, black becomes white
+            print(f"Applied invert_mask=False: inverted RGB mask (now black=remove)")
     
     # Resize mask to match image dimensions
     if size_limit < max_dimension: