mmsegmentation/mmseg/models/backbones/mobile_net_v2.py

58 lines
1.6 KiB
Python

from mmcv.cnn import ConvModule, build_norm_layer
from torch import nn
class InvertedResidual(nn.Module):
def __init__(self,
inp,
oup,
stride,
expand_ratio,
dilation=1,
conv_cfg=None,
norm_cfg=dict(type='BN'),
act_cfg=dict(type='ReLU6')):
super(InvertedResidual, self).__init__()
self.stride = stride
assert stride in [1, 2]
hidden_dim = int(round(inp * expand_ratio))
self.use_res_connect = self.stride == 1 and inp == oup
layers = []
if expand_ratio != 1:
# pw
layers.append(
ConvModule(
inp,
hidden_dim,
kernel_size=1,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg,
act_cfg=act_cfg))
layers.extend([
# dw
ConvModule(
hidden_dim,
hidden_dim,
kernel_size=3,
padding=dilation,
stride=stride,
dilation=dilation,
groups=hidden_dim,
conv_cfg=conv_cfg,
norm_cfg=norm_cfg,
act_cfg=act_cfg),
# pw-linear
nn.Conv2d(hidden_dim, oup, 1, 1, 0, bias=False),
build_norm_layer(norm_cfg, oup)[1],
])
self.conv = nn.Sequential(*layers)
def forward(self, x):
if self.use_res_connect:
return x + self.conv(x)
else:
return self.conv(x)