Upload encoders/xception.py

encoders/xception.py

@@ -0,0 +1,66 @@
+import re
+import torch.nn as nn
+
+from pretrainedmodels.models.xception import pretrained_settings
+from pretrainedmodels.models.xception import Xception
+
+from ._base import EncoderMixin
+
+
+class XceptionEncoder(Xception, EncoderMixin):
+
+    def __init__(self, out_channels, *args, depth=5, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self._out_channels = out_channels
+        self._depth = depth
+        self._in_channels = 3
+
+        # modify padding to maintain output shape
+        self.conv1.padding = (1, 1)
+        self.conv2.padding = (1, 1)
+
+        del self.fc
+
+    def make_dilated(self, stage_list, dilation_list):
+        raise ValueError("Xception encoder does not support dilated mode "
+                         "due to pooling operation for downsampling!")
+
+    def get_stages(self):
+        return [
+            nn.Identity(),
+            nn.Sequential(self.conv1, self.bn1, self.relu, self.conv2, self.bn2, self.relu),
+            self.block1,
+            self.block2,
+            nn.Sequential(self.block3, self.block4, self.block5, self.block6, self.block7,
+                          self.block8, self.block9, self.block10, self.block11),
+            nn.Sequential(self.block12, self.conv3, self.bn3, self.relu, self.conv4, self.bn4),
+        ]
+
+    def forward(self, x):
+        stages = self.get_stages()
+
+        features = []
+        for i in range(self._depth + 1):
+            x = stages[i](x)
+            features.append(x)
+
+        return features
+
+    def load_state_dict(self, state_dict):
+        # remove linear
+        state_dict.pop('fc.bias', None)
+        state_dict.pop('fc.weight', None)
+
+        super().load_state_dict(state_dict)
+
+
+xception_encoders = {
+    'xception': {
+        'encoder': XceptionEncoder,
+        'pretrained_settings': pretrained_settings['xception'],
+        'params': {
+            'out_channels': (3, 64, 128, 256, 728, 2048),
+        }
+    },
+}