add unet (open-mmlab#161)

* add unet

* add unet

* add unet

* update test_unet

* update test_unet

* update test_unet

* update test_unet

* fix bugs

* add init method for unet

* add test of UNet init_weights method

* add registry

* merge upsample

* fix test

* Update mmseg/models/backbones/unet.py

Co-authored-by: Jerry Jiarui XU <[email protected]>

* Update mmseg/models/backbones/unet.py

Co-authored-by: Jerry Jiarui XU <[email protected]>

* split UpConvBlock from UNet

* use reversed

* rename upsample module

* rename upsample module

* rename upsample module

* rename upsample module

Co-authored-by: Jerry Jiarui XU <[email protected]>

Author: Junjun2016

mmseg/models/backbones/__init__.py

@@ -4,8 +4,9 @@
 from .resnest import ResNeSt
 from .resnet import ResNet, ResNetV1c, ResNetV1d
 from .resnext import ResNeXt
+from .unet import UNet
 
 __all__ = [
     'ResNet', 'ResNetV1c', 'ResNetV1d', 'ResNeXt', 'HRNet', 'FastSCNN',
-    'ResNeSt', 'MobileNetV2'
+    'ResNeSt', 'MobileNetV2', 'UNet'
 ]