目录
0. 添加方法
主要步骤:
(1)在
models/common.py
中注册注意力模块
(2)在
models/yolo.py
中的
parse_model
函数中添加注意力模块
(3)修改配置文件
yolov5s.yaml
(4)运行
yolo.py
进行验证
各个注意力机制模块的添加方法类似,各注意力模块的修改参照SE。
本文添加注意力完整代码:https://github.com/double-vin/yolov5_attention
1. SE
Squeeze-and-Excitation Networks
https://github.com/hujie-frank/SENet
1.1 SE
- 在
models/common.py
中注册SE模块
classSE(nn.Module):def__init__(self, c1, c2, ratio=16):super(SE, self).__init__()#c*1*1
self.avgpool = nn.AdaptiveAvgPool2d(1)
self.l1 = nn.Linear(c1, c1 // ratio, bias=False)
self.relu = nn.ReLU(inplace=True)
self.l2 = nn.Linear(c1 // ratio, c1, bias=False)
self.sig = nn.Sigmoid()defforward(self, x):
b, c, _, _ = x.size()
y = self.avgpool(x).view(b, c)
y = self.l1(y)
y = self.relu(y)
y = self.l2(y)
y = self.sig(y)
y = y.view(b, c,1,1)return x * y.expand_as(x)
- 在
models/yolo.py
中的parse_model
函数中添加SE模块 - 修改配置文件
yolov5s.yaml
。 添加注意力的两种方法:一是在backbone的最后一层添加注意力;二是将backbone中的C3全部替换。 这里使用第一种,第二种见下文中的C3SE
注意:SE添加至第9层,第9层之后所有的编号都要+1,则: 1>两个Concat
的from系数分别由[-1, 14],[-1, 10]改为[-1, 15],[-1, 11] 2>Detect
的from系数由[17, 20, 23]改为[18,21,24] - 验证:运行
yolo.py
1.2 C3-SE
- 在
models/common.py
中注册C3SE模块:
classSEBottleneck(nn.Module):# Standard bottleneckdef__init__(self, c1, c2, shortcut=True, g=1, e=0.5, ratio=16):# ch_in, ch_out, shortcut, groups, expansionsuper().__init__()
c_ =int(c2 * e)# hidden channels
self.cv1 = Conv(c1, c_,1,1)
self.cv2 = Conv(c_, c2,3,1, g=g)
self.add = shortcut and c1 == c2
# self.se=SE(c1,c2,ratio)
self.avgpool = nn.AdaptiveAvgPool2d(1)
self.l1 = nn.Linear(c1, c1 // ratio, bias=False)
self.relu = nn.ReLU(inplace=True)
self.l2 = nn.Linear(c1 // ratio, c1, bias=False)
self.sig = nn.Sigmoid()defforward(self, x):
x1 = self.cv2(self.cv1(x))
b, c, _, _ = x.size()
y = self.avgpool(x1).view(b, c)
y = self.l1(y)
y = self.relu(y)
y = self.l2(y)
y = self.sig(y)
y = y.view(b, c,1,1)
out = x1 * y.expand_as(x1)# out=self.se(x1)*x1return x + out if self.add else out
classC3SE(C3):# C3 module with SEBottleneck()def__init__(self, c1, c2, n=1, shortcut=True, g=1, e=0.5):super().__init__(c1, c2, n, shortcut, g, e)
c_ =int(c2 * e)# hidden channels
self.m = nn.Sequential(*(SEBottleneck(c_, c_, shortcut)for _ inrange(n)))
- 在
models/yolo.py
中的parse_model
函数中添加C3SE模块 - 修改配置文件
yolov5s.yaml
。 - 验证:运行
yolo.py
2. CBAM
《CBAM: Convolutional Block Attention Module》
2.1 CBAM
classChannelAttention(nn.Module):def__init__(self, in_planes, ratio=16):super(ChannelAttention, self).__init__()
self.avg_pool = nn.AdaptiveAvgPool2d(1)
self.max_pool = nn.AdaptiveMaxPool2d(1)
self.f1 = nn.Conv2d(in_planes, in_planes // ratio,1, bias=False)
self.relu = nn.ReLU()
self.f2 = nn.Conv2d(in_planes // ratio, in_planes,1, bias=False)
self.sigmoid = nn.Sigmoid()defforward(self, x):
avg_out = self.f2(self.relu(self.f1(self.avg_pool(x))))
max_out = self.f2(self.relu(self.f1(self.max_pool(x))))
out = self.sigmoid(avg_out + max_out)return out
classSpatialAttention(nn.Module):def__init__(self, kernel_size=7):super(SpatialAttention, self).__init__()assert kernel_size in(3,7),'kernel size must be 3 or 7'
padding =3if kernel_size ==7else1# (特征图的大小-算子的size+2*padding)/步长+1
self.conv = nn.Conv2d(2,1, kernel_size, padding=padding, bias=False)
self.sigmoid = nn.Sigmoid()defforward(self, x):# 1*h*w
avg_out = torch.mean(x, dim=1, keepdim=True)
max_out, _ = torch.max(x, dim=1, keepdim=True)
x = torch.cat([avg_out, max_out], dim=1)#2*h*w
x = self.conv(x)#1*h*wreturn self.sigmoid(x)classCBAM(nn.Module):# CSP Bottleneck with 3 convolutionsdef__init__(self, c1, c2, ratio=16, kernel_size=7):# ch_in, ch_out, number, shortcut, groups, expansionsuper(CBAM, self).__init__()
self.channel_attention = ChannelAttention(c1, ratio)
self.spatial_attention = SpatialAttention(kernel_size)defforward(self, x):
out = self.channel_attention(x)* x
# c*h*w# c*h*w * 1*h*w
out = self.spatial_attention(out)* out
return out
2.2 C3-CBAM
classCBAMBottleneck(nn.Module):# Standard bottleneckdef__init__(self, c1, c2, shortcut=True, g=1, e=0.5,ratio=16,kernel_size=7):# ch_in, ch_out, shortcut, groups, expansionsuper(CBAMBottleneck,self).__init__()
c_ =int(c2 * e)# hidden channels
self.cv1 = Conv(c1, c_,1,1)
self.cv2 = Conv(c_, c2,3,1, g=g)
self.add = shortcut and c1 == c2
self.channel_attention = ChannelAttention(c2, ratio)
self.spatial_attention = SpatialAttention(kernel_size)#self.cbam=CBAM(c1,c2,ratio,kernel_size)defforward(self, x):
x1 = self.cv2(self.cv1(x))
out = self.channel_attention(x1)* x1
# print('outchannels:{}'.format(out.shape))
out = self.spatial_attention(out)* out
return x + out if self.add else out
classC3CBAM(C3):# C3 module with CBAMBottleneck()def__init__(self, c1, c2, n=1, shortcut=True, g=1, e=0.5):super().__init__(c1, c2, n, shortcut, g, e)
c_ =int(c2 * e)# hidden channels
self.m = nn.Sequential(*(CBAMBottleneck(c_, c_, shortcut)for _ inrange(n)))
3. ECA
《ECA-Net: Efficient Channel Attention for Deep Convolutional Neural Networks》
https://github.com/BangguWu/ECANet
3.1 ECA
classECA(nn.Module):"""Constructs a ECA module.
Args:
channel: Number of channels of the input feature map
k_size: Adaptive selection of kernel size
"""def__init__(self, c1, c2, k_size=3):super(ECA, self).__init__()
self.avg_pool = nn.AdaptiveAvgPool2d(1)
self.conv = nn.Conv1d(1,1, kernel_size=k_size, padding=(k_size -1)//2, bias=False)
self.sigmoid = nn.Sigmoid()defforward(self, x):# feature descriptor on the global spatial information
y = self.avg_pool(x)# print(y.shape,y.squeeze(-1).shape,y.squeeze(-1).transpose(-1, -2).shape)# Two different branches of ECA module# 50*C*1*1# 50*C*1# 50*1*C
y = self.conv(y.squeeze(-1).transpose(-1,-2)).transpose(-1,-2).unsqueeze(-1)# Multi-scale information fusion
y = self.sigmoid(y)return x * y.expand_as(x)
3.2 C3-ECA
classECABottleneck(nn.Module):# Standard bottleneckdef__init__(self, c1, c2, shortcut=True, g=1, e=0.5, ratio=16, k_size=3):# ch_in, ch_out, shortcut, groups, expansionsuper().__init__()
c_ =int(c2 * e)# hidden channels
self.cv1 = Conv(c1, c_,1,1)
self.cv2 = Conv(c_, c2,3,1, g=g)
self.add = shortcut and c1 == c2
# self.eca=ECA(c1,c2)
self.avg_pool = nn.AdaptiveAvgPool2d(1)
self.conv = nn.Conv1d(1,1, kernel_size=k_size, padding=(k_size -1)//2, bias=False)
self.sigmoid = nn.Sigmoid()defforward(self, x):
x1 = self.cv2(self.cv1(x))# out=self.eca(x1)*x1
y = self.avg_pool(x1)
y = self.conv(y.squeeze(-1).transpose(-1,-2)).transpose(-1,-2).unsqueeze(-1)
y = self.sigmoid(y)
out = x1 * y.expand_as(x1)return x + out if self.add else out
classC3ECA(C3):# C3 module with ECABottleneck()def__init__(self, c1, c2, n=1, shortcut=True, g=1, e=0.5):super().__init__(c1, c2, n, shortcut, g, e)
c_ =int(c2 * e)# hidden channels
self.m = nn.Sequential(*(ECABottleneck(c_, c_, shortcut)for _ inrange(n)))
4. CA
Coordinate Attention for Efficient Mobile Network Design
https://github.com/Andrew-Qibin/CoordAttention
4.1 CA
classh_sigmoid(nn.Module):def__init__(self, inplace=True):super(h_sigmoid, self).__init__()
self.relu = nn.ReLU6(inplace=inplace)defforward(self, x):return self.relu(x +3)/6classh_swish(nn.Module):def__init__(self, inplace=True):super(h_swish, self).__init__()
self.sigmoid = h_sigmoid(inplace=inplace)defforward(self, x):return x * self.sigmoid(x)classCoordAtt(nn.Module):def__init__(self, inp, oup, reduction=32):super(CoordAtt, self).__init__()
self.pool_h = nn.AdaptiveAvgPool2d((None,1))
self.pool_w = nn.AdaptiveAvgPool2d((1,None))
mip =max(8, inp // reduction)
self.conv1 = nn.Conv2d(inp, mip, kernel_size=1, stride=1, padding=0)
self.bn1 = nn.BatchNorm2d(mip)
self.act = h_swish()
self.conv_h = nn.Conv2d(mip, oup, kernel_size=1, stride=1, padding=0)
self.conv_w = nn.Conv2d(mip, oup, kernel_size=1, stride=1, padding=0)defforward(self, x):
identity = x
n, c, h, w = x.size()# c*1*W
x_h = self.pool_h(x)# c*H*1# C*1*h
x_w = self.pool_w(x).permute(0,1,3,2)
y = torch.cat([x_h, x_w], dim=2)# C*1*(h+w)
y = self.conv1(y)
y = self.bn1(y)
y = self.act(y)
x_h, x_w = torch.split(y,[h, w], dim=2)
x_w = x_w.permute(0,1,3,2)
a_h = self.conv_h(x_h).sigmoid()
a_w = self.conv_w(x_w).sigmoid()
out = identity * a_w * a_h
return out
4.2 C3-CA
classCABottleneck(nn.Module):# Standard bottleneckdef__init__(self, c1, c2, shortcut=True, g=1, e=0.5, ratio=32):# ch_in, ch_out, shortcut, groups, expansionsuper().__init__()
c_ =int(c2 * e)# hidden channels
self.cv1 = Conv(c1, c_,1,1)
self.cv2 = Conv(c_, c2,3,1, g=g)
self.add = shortcut and c1 == c2
# self.ca=CoordAtt(c1,c2,ratio)
self.pool_h = nn.AdaptiveAvgPool2d((None,1))
self.pool_w = nn.AdaptiveAvgPool2d((1,None))
mip =max(8, c1 // ratio)
self.conv1 = nn.Conv2d(c1, mip, kernel_size=1, stride=1, padding=0)
self.bn1 = nn.BatchNorm2d(mip)
self.act = h_swish()
self.conv_h = nn.Conv2d(mip, c2, kernel_size=1, stride=1, padding=0)
self.conv_w = nn.Conv2d(mip, c2, kernel_size=1, stride=1, padding=0)defforward(self, x):
x1=self.cv2(self.cv1(x))
n, c, h, w = x.size()# c*1*W
x_h = self.pool_h(x1)# c*H*1# C*1*h
x_w = self.pool_w(x1).permute(0,1,3,2)
y = torch.cat([x_h, x_w], dim=2)# C*1*(h+w)
y = self.conv1(y)
y = self.bn1(y)
y = self.act(y)
x_h, x_w = torch.split(y,[h, w], dim=2)
x_w = x_w.permute(0,1,3,2)
a_h = self.conv_h(x_h).sigmoid()
a_w = self.conv_w(x_w).sigmoid()
out = x1 * a_w * a_h
# out=self.ca(x1)*x1return x + out if self.add else out
classC3CA(C3):# C3 module with CABottleneck()def__init__(self, c1, c2, n=1, shortcut=True, g=1, e=0.5):super().__init__(c1, c2, n, shortcut, g, e)
c_ =int(c2 * e)# hidden channels
self.m = nn.Sequential(*(CABottleneck(c_, c_,shortcut)for _ inrange(n)))
Tips:添加注意力的位置不局限,可以尝试各种排列组合
参考:
多种注意力介绍
添加注意力视频讲解
添加CBAM
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