Merge pull request #2334 from MengzhangLI/fix_knet_dev1.x

[Fix] Fix KNet IterativeDecodeHead bug in dev-1.x branch

mmseg/models/decode_heads/knet_head.py

@@ -413,6 +413,9 @@ class IterativeDecodeHead(BaseDecodeHead):
 
  def __init__(self, num_stages, kernel_generate_head, kernel_update_head,
  **kwargs):
+ # ``IterativeDecodeHead`` would skip initialization of
+ # ``BaseDecodeHead`` which would be called when building
+ # ``self.kernel_generate_head``.
  super(BaseDecodeHead, self).__init__(**kwargs)
  assert num_stages == len(kernel_update_head)
  self.num_stages = num_stages
@@ -422,6 +425,7 @@ def __init__(self, num_stages, kernel_generate_head, kernel_update_head,
  self.num_classes = self.kernel_generate_head.num_classes
  self.input_transform = self.kernel_generate_head.input_transform
  self.ignore_index = self.kernel_generate_head.ignore_index
+ self.out_channels = self.num_classes
 
  for head_cfg in kernel_update_head:
  self.kernel_update_head.append(MODELS.build(head_cfg))