每日Attention学习28——Strip Pooling
模块出处
[CVPR 20] [link] Strip Pooling: Rethinking Spatial Pooling for Scene Parsing
模块名称
Strip Pooling (SP)
模块结构
模块特点
- 本质是空间注意力的一种
- 使用横/纵两个方向的条形池化获得一维方向上的重要程度,结合后便可以扩展至二维方向
模块代码
import torch
import torch.nn as nn
import torch.nn.functional as F
class SP(nn.Module):
def __init__(self, in_channels, pool_size):
super(SP, self).__init__()
self.pool1 = nn.AdaptiveAvgPool2d(pool_size[0])
self.pool2 = nn.AdaptiveAvgPool2d(pool_size[1])
self.pool3 = nn.AdaptiveAvgPool2d((1, None))
self.pool4 = nn.AdaptiveAvgPool2d((None, 1))
inter_channels = int(in_channels/4)
self.conv1_1 = nn.Sequential(nn.Conv2d(in_channels, inter_channels, 1, bias=False),
nn.BatchNorm2d(inter_channels),
nn.ReLU(True))
self.conv1_2 = nn.Sequential(nn.Conv2d(in_channels, inter_channels, 1, bias=False),
nn.BatchNorm2d(inter_channels),
nn.ReLU(True))
self.conv2_0 = nn.Sequential(nn.Conv2d(inter_channels, inter_channels, 3, 1, 1, bias=False),
nn.BatchNorm2d(inter_channels))
self.conv2_1 = nn.Sequential(nn.Conv2d(inter_channels, inter_channels, 3, 1, 1, bias=False),
nn.BatchNorm2d(inter_channels))
self.conv2_2 = nn.Sequential(nn.Conv2d(inter_channels, inter_channels, 3, 1, 1, bias=False),
nn.BatchNorm2d(inter_channels))
self.conv2_3 = nn.Sequential(nn.Conv2d(inter_channels, inter_channels, (1, 3), 1, (0, 1), bias=False),
nn.BatchNorm2d(inter_channels))
self.conv2_4 = nn.Sequential(nn.Conv2d(inter_channels, inter_channels, (3, 1), 1, (1, 0), bias=False),
nn.BatchNorm2d(inter_channels))
self.conv2_5 = nn.Sequential(nn.Conv2d(inter_channels, inter_channels, 3, 1, 1, bias=False),
nn.BatchNorm2d(inter_channels),
nn.ReLU(True))
self.conv2_6 = nn.Sequential(nn.Conv2d(inter_channels, inter_channels, 3, 1, 1, bias=False),
nn.BatchNorm2d(inter_channels),
nn.ReLU(True))
self.conv3 = nn.Sequential(nn.Conv2d(inter_channels*2, in_channels, 1, bias=False),
nn.BatchNorm2d(in_channels))
def forward(self, x):
_, _, h, w = x.size()
x1 = self.conv1_1(x)
x2 = self.conv1_2(x)
x2_1 = self.conv2_0(x1)
x2_2 = F.interpolate(self.conv2_1(self.pool1(x1)), (h, w))
x2_3 = F.interpolate(self.conv2_2(self.pool2(x1)), (h, w))
x2_4 = F.interpolate(self.conv2_3(self.pool3(x2)), (h, w))
x2_5 = F.interpolate(self.conv2_4(self.pool4(x2)), (h, w))
x1 = self.conv2_5(F.relu_(x2_1 + x2_2 + x2_3))
x2 = self.conv2_6(F.relu_(x2_5 + x2_4))
out = self.conv3(torch.cat([x1, x2], dim=1))
return F.relu_(x + out)
if __name__ == '__main__':
x = torch.randn([1, 64, 44, 44])
sp = SP(in_channels=64, pool_size=(8, 8))
out = sp(x)
print(out.shape) # [1, 64, 44, 44]