init

finetune/mmseg/models/decode_heads/gc_head.py

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+# Copyright (c) OpenMMLab. All rights reserved.
+import torch
+from mmcv.cnn import ContextBlock
+
+from mmseg.registry import MODELS
+from .fcn_head import FCNHead
+
+
+@MODELS.register_module()
+class GCHead(FCNHead):
+    """GCNet: Non-local Networks Meet Squeeze-Excitation Networks and Beyond.
+
+    This head is the implementation of `GCNet
+    <https://arxiv.org/abs/1904.11492>`_.
+
+    Args:
+        ratio (float): Multiplier of channels ratio. Default: 1/4.
+        pooling_type (str): The pooling type of context aggregation.
+            Options are 'att', 'avg'. Default: 'avg'.
+        fusion_types (tuple[str]): The fusion type for feature fusion.
+            Options are 'channel_add', 'channel_mul'. Default: ('channel_add',)
+    """
+
+    def __init__(self,
+                 ratio=1 / 4.,
+                 pooling_type='att',
+                 fusion_types=('channel_add', ),
+                 **kwargs):
+        super().__init__(num_convs=2, **kwargs)
+        self.ratio = ratio
+        self.pooling_type = pooling_type
+        self.fusion_types = fusion_types
+        self.gc_block = ContextBlock(
+            in_channels=self.channels,
+            ratio=self.ratio,
+            pooling_type=self.pooling_type,
+            fusion_types=self.fusion_types)
+
+    def forward(self, inputs):
+        """Forward function."""
+        x = self._transform_inputs(inputs)
+        output = self.convs[0](x)
+        output = self.gc_block(output)
+        output = self.convs[1](output)
+        if self.concat_input:
+            output = self.conv_cat(torch.cat([x, output], dim=1))
+        output = self.cls_seg(output)
+        return output