unravel multi-view img to list

mmdet3d/datasets/pipelines/loading.py

@@ -41,12 +41,15 @@ def __call__(self, results):
                 - img_norm_cfg (dict): Normalization configuration of images.
         """
         filename = results['img_filename']
+        # img is of shape (h, w, c, num_views)
         img = np.stack(
             [mmcv.imread(name, self.color_type) for name in filename], axis=-1)
         if self.to_float32:
             img = img.astype(np.float32)
         results['filename'] = filename
-        results['img'] = img
+        # unravel to list, see `DefaultFormatBundle` in formating.py
+        # which will transpose each image separately and then stack into array
+        results['img'] = [img[..., i] for i in range(img.shape[-1])]
         results['img_shape'] = img.shape
         results['ori_shape'] = img.shape
         # Set initial values for default meta_keys
@@ -61,8 +64,10 @@ def __call__(self, results):
 
     def __repr__(self):
         """str: Return a string that describes the module."""
-        return f'{self.__class__.__name__} (to_float32={self.to_float32}, '\
-            f"color_type='{self.color_type}')"
+        repr_str = self.__class__.__name__
+        repr_str += f'(to_float32={self.to_float32}, '
+        repr_str += f"color_type='{self.color_type}')"
+        return repr_str
 
 
 @PIPELINES.register_module()