title: Mask R-CNN, Multi-Class
body: <p>I am following the classic balloon example of Mask R-CNN. I trained the model with 2 classes, vehicle and bottle. Now the model perfectly detects both of the objects but It says vehicle (class_id=1) to all of them, where it would say all bottles are vehicle. I probably made some mistakes while configuring the code. Does anybody have an idea about this issue?</p>
  
  <p>Changed the number of classes in the config.py (1 + nb classes)
  Added these classes in load_ in the custom dataset class</p>
  
  <p>But I think I need to do one more thing and It is about here:</p>
  
  <pre><code> for a in annotations:
          # print(a)
          # Get the x, y coordinates of points of the polygons that make up
          # the outline of each object instance. There are stores in the
          # shape_attributes (see json format above)
          polygons = [r['shape_attributes'] for r in a['regions'].values()]
  
          # load_mask() needs the image size to convert polygons to masks.
          # Unfortunately, VIA doesn't include it in JSON, so we must read
          # the image. This is only managable since the dataset is tiny.
          image_path = os.path.join(dataset_dir, a['filename'])
          image = skimage.io.imread(image_path)
          height, width = image.shape[:2]
  
          self.add_image(
              "vehicle",  ## for a single class just add the name here
              image_id=a['filename'],  # use file name as a unique image id
              path=image_path,
              width=width, height=height,
              polygons=polygons)
  </code></pre>
  
  <p>I couldn't figure out what to change in here. Thank you for your time.</p>