Add seg transform to Expand and MinIoUCrop (#1550)

* Add seg transform to Expand and MinIoUCrop

* fix bug of repr

mmdet/datasets/pipelines/transforms.py

@@ -511,12 +511,19 @@ class Expand(object):
         ratio_range (tuple): range of expand ratio.
     """
 
-    def __init__(self, mean=(0, 0, 0), to_rgb=True, ratio_range=(1, 4)):
+    def __init__(self,
+                 mean=(0, 0, 0),
+                 to_rgb=True,
+                 ratio_range=(1, 4),
+                 seg_ignore_label=None):
+        self.to_rgb = to_rgb
+        self.ratio_range = ratio_range
         if to_rgb:
             self.mean = mean[::-1]
         else:
             self.mean = mean
         self.min_ratio, self.max_ratio = ratio_range
+        self.seg_ignore_label = seg_ignore_label
 
     def __call__(self, results):
         if random.randint(2):
@@ -544,12 +551,23 @@ class Expand(object):
                 expand_mask[top:top + h, left:left + w] = mask
                 expand_gt_masks.append(expand_mask)
             results['gt_masks'] = expand_gt_masks
+
+        # not tested
+        if 'gt_semantic_seg' in results:
+            assert self.seg_ignore_label is not None
+            gt_seg = results['gt_semantic_seg']
+            expand_gt_seg = np.full((int(h * ratio), int(w * ratio)),
+                                    self.seg_ignore_label).astype(gt_seg.dtype)
+            expand_gt_seg[top:top + h, left:left + w] = gt_seg
+            results['gt_semantic_seg'] = expand_gt_seg
         return results
 
     def __repr__(self):
         repr_str = self.__class__.__name__
-        repr_str += '(mean={}, to_rgb={}, ratio_range={})'.format(
-            self.mean, self.to_rgb, self.ratio_range)
+        repr_str += '(mean={}, to_rgb={}, ratio_range={}, ' \
+                    'seg_ignore_label={})'.format(
+                        self.mean, self.to_rgb, self.ratio_range,
+                        self.seg_ignore_label)
         return repr_str
 
 
@@ -626,6 +644,11 @@ class MinIoURandomCrop(object):
                         gt_mask[patch[1]:patch[3], patch[0]:patch[2]]
                         for gt_mask in valid_masks
                     ]
+
+                # not tested
+                if 'gt_semantic_seg' in results:
+                    results['gt_semantic_seg'] = results['gt_semantic_seg'][
+                        patch[1]:patch[3], patch[0]:patch[2]]
                 return results
 
     def __repr__(self):