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YOLO11改进 | 注意力机制 | 添加多种注意力机制,开箱即用

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本文介绍了YOLO11添加ResBlock_CBAM, CBAM, GAM, ECAAttention, GCnet_GlobalContext, GEnet等多种注意力机制。文章在介绍主要的原理后,将手把手教学如何进行模块的代码添加和修改,并将修改后的完整代码放在文章的最后,方便大家一键运行,小白也可轻松上手实践。以帮助您更好地学习深度学习目标检测YOLO系列的挑战。

专栏地址:YOLO11入门 + 改进涨点——点击即可跳转 欢迎订阅

目录

1. 论文

2. 添加注意力机制到YOLO11中

2.1 将注意力机制添加到YOLO11中

2.2 更改init.py文件

2.3 添加yaml文件

2.4 在task.py中进行注册

2.5 执行程序

3.修改后的网络结构图

4. 完整代码分享

5. GFLOPs

6. 其他注意力机制

7. 进阶

8.总结


1. 论文

论文链接:CBAM: Convolutional Block Attention Module——点击即可跳转

官方代码:官方代码仓库——点击即可跳转 

以CBAM为例子,其他的只换代码,步骤不变

2. 添加注意力机制到YOLO11中

2.1 将注意力机制添加到YOLO11中

关键步骤一: 将下面代码粘贴到在/ultralytics/ultralytics/nn/modules/blcok.py中

class ChannelAttention(nn.Module):
    """Channel-attention module https://github.com/open-mmlab/mmdetection/tree/v3.0.0rc1/configs/rtmdet."""
 
    def __init__(self, channels: int) -> None:
        super().__init__()
        self.pool = nn.AdaptiveAvgPool2d(1)
        self.fc = nn.Conv2d(channels, channels, 1, 1, 0, bias=True)
        self.act = nn.Sigmoid()
 
    def forward(self, x: torch.Tensor) -> torch.Tensor:
        return x * self.act(self.fc(self.pool(x)))
 
 
class SpatialAttention(nn.Module):
    """Spatial-attention module."""
 
    def __init__(self, kernel_size=7):
        """Initialize Spatial-attention module with kernel size argument."""
        super().__init__()
        assert kernel_size in (3, 7), 'kernel size must be 3 or 7'
        padding = 3 if kernel_size == 7 else 1
        self.cv1 = nn.Conv2d(2, 1, kernel_size, padding=padding, bias=False)
        self.act = nn.Sigmoid()
 
    def forward(self, x):
        """Apply channel and spatial attention on input for feature recalibration."""
        return x * self.act(self.cv1(torch.cat([torch.mean(x, 1, keepdim=True), torch.max(x, 1, keepdim=True)[0]], 1)))
 
 
class CBAM(nn.Module):
    """Convolutional Block Attention Module."""
 
    def __init__(self, c1, kernel_size=7):  # ch_in, kernels
        super().__init__()
        self.channel_attention = ChannelAttention(c1)
        self.spatial_attention = SpatialAttention(kernel_size)
 
    def forward(self, x):
        """Applies the forward pass through C1 module."""
        return self.spatial_attention(self.channel_attention(x))

 CBAM注意力机制原理及代码实现

CBAM注意力机制结构图

2.2 更改init.py文件

关键步骤二:修改modules文件夹下的__init__.py文件,先导入函数

然后在下面的__all__中声明函数

2.3 添加yaml文件

关键步骤三:在/ultralytics/ultralytics/cfg/models/11下面新建文件yolo11_CBAM.yaml文件,粘贴下面的内容

  • 目标检测
# Ultralytics YOLO 🚀, AGPL-3.0 license
# YOLO11 object detection model with P3-P5 outputs. For Usage examples see https://docs.ultralytics.com/tasks/detect

# Parameters
nc: 80 # number of classes
scales: # model compound scaling constants, i.e. 'model=yolo11n.yaml' will call yolo11.yaml with scale 'n'
  # [depth, width, max_channels]
  n: [0.50, 0.25, 1024] # summary: 319 layers, 2624080 parameters, 2624064 gradients, 6.6 GFLOPs
  s: [0.50, 0.50, 1024] # summary: 319 layers, 9458752 parameters, 9458736 gradients, 21.7 GFLOPs
  m: [0.50, 1.00, 512] # summary: 409 layers, 20114688 parameters, 20114672 gradients, 68.5 GFLOPs
  l: [1.00, 1.00, 512] # summary: 631 layers, 25372160 parameters, 25372144 gradients, 87.6 GFLOPs
  x: [1.00, 1.50, 512] # summary: 631 layers, 56966176 parameters, 56966160 gradients, 196.0 GFLOPs

# YOLO11n backbone
backbone:
  # [from, repeats, module, args]
  - [-1, 1, Conv, [64, 3, 2]] # 0-P1/2
  - [-1, 1, Conv, [128, 3, 2]] # 1-P2/4
  - [-1, 2, C3k2, [256, False, 0.25]]
  - [-1, 1, Conv, [256, 3, 2]] # 3-P3/8
  - [-1, 2, C3k2, [512, False, 0.25]]
  - [-1, 1, Conv, [512, 3, 2]] # 5-P4/16
  - [-1, 2, C3k2, [512, True]]
  - [-1, 1, Conv, [1024, 3, 2]] # 7-P5/32
  - [-1, 2, C3k2, [1024, True]]
  - [-1, 1, CBAM, [1024]]
  - [-1, 1, SPPF, [1024, 5]] # 9
  - [-1, 2, C2PSA, [1024]] # 10

# YOLO11n head
head:
  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [[-1, 6], 1, Concat, [1]] # cat backbone P4
  - [-1, 2, C3k2, [512, False]] # 13

  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [[-1, 4], 1, Concat, [1]] # cat backbone P3
  - [-1, 2, C3k2, [256, False]] # 16 (P3/8-small)

  - [-1, 1, Conv, [256, 3, 2]]
  - [[-1, 14], 1, Concat, [1]] # cat head P4
  - [-1, 2, C3k2, [512, False]] # 19 (P4/16-medium)

  - [-1, 1, Conv, [512, 3, 2]]
  - [[-1, 11], 1, Concat, [1]] # cat head P5
  - [-1, 2, C3k2, [1024, True]] # 22 (P5/32-large)

  - [[17, 20, 23], 1, Detect, [nc]] # Detect(P3, P4, P5)
  • 语义分割
# Ultralytics YOLO 🚀, AGPL-3.0 license
# YOLO11 object detection model with P3-P5 outputs. For Usage examples see https://docs.ultralytics.com/tasks/detect

# Parameters
nc: 80 # number of classes
scales: # model compound scaling constants, i.e. 'model=yolo11n.yaml' will call yolo11.yaml with scale 'n'
  # [depth, width, max_channels]
  n: [0.50, 0.25, 1024] # summary: 319 layers, 2624080 parameters, 2624064 gradients, 6.6 GFLOPs
  s: [0.50, 0.50, 1024] # summary: 319 layers, 9458752 parameters, 9458736 gradients, 21.7 GFLOPs
  m: [0.50, 1.00, 512] # summary: 409 layers, 20114688 parameters, 20114672 gradients, 68.5 GFLOPs
  l: [1.00, 1.00, 512] # summary: 631 layers, 25372160 parameters, 25372144 gradients, 87.6 GFLOPs
  x: [1.00, 1.50, 512] # summary: 631 layers, 56966176 parameters, 56966160 gradients, 196.0 GFLOPs

# YOLO11n backbone
backbone:
  # [from, repeats, module, args]
  - [-1, 1, Conv, [64, 3, 2]] # 0-P1/2
  - [-1, 1, Conv, [128, 3, 2]] # 1-P2/4
  - [-1, 2, C3k2, [256, False, 0.25]]
  - [-1, 1, Conv, [256, 3, 2]] # 3-P3/8
  - [-1, 2, C3k2, [512, False, 0.25]]
  - [-1, 1, Conv, [512, 3, 2]] # 5-P4/16
  - [-1, 2, C3k2, [512, True]]
  - [-1, 1, Conv, [1024, 3, 2]] # 7-P5/32
  - [-1, 2, C3k2, [1024, True]]
  - [-1, 1, CBAM, [1024]]
  - [-1, 1, SPPF, [1024, 5]] # 9
  - [-1, 2, C2PSA, [1024]] # 10

# YOLO11n head
head:
  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [[-1, 6], 1, Concat, [1]] # cat backbone P4
  - [-1, 2, C3k2, [512, False]] # 13

  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [[-1, 4], 1, Concat, [1]] # cat backbone P3
  - [-1, 2, C3k2, [256, False]] # 16 (P3/8-small)

  - [-1, 1, Conv, [256, 3, 2]]
  - [[-1, 14], 1, Concat, [1]] # cat head P4
  - [-1, 2, C3k2, [512, False]] # 19 (P4/16-medium)

  - [-1, 1, Conv, [512, 3, 2]]
  - [[-1, 11], 1, Concat, [1]] # cat head P5
  - [-1, 2, C3k2, [1024, True]] # 22 (P5/32-large)

  - [[17, 20, 23], 1, Segment, [nc, 32, 256]] # Segment(P3, P4, P5)
  • 旋转目标检测
# Ultralytics YOLO 🚀, AGPL-3.0 license
# YOLO11 object detection model with P3-P5 outputs. For Usage examples see https://docs.ultralytics.com/tasks/detect

# Parameters
nc: 80 # number of classes
scales: # model compound scaling constants, i.e. 'model=yolo11n.yaml' will call yolo11.yaml with scale 'n'
  # [depth, width, max_channels]
  n: [0.50, 0.25, 1024] # summary: 319 layers, 2624080 parameters, 2624064 gradients, 6.6 GFLOPs
  s: [0.50, 0.50, 1024] # summary: 319 layers, 9458752 parameters, 9458736 gradients, 21.7 GFLOPs
  m: [0.50, 1.00, 512] # summary: 409 layers, 20114688 parameters, 20114672 gradients, 68.5 GFLOPs
  l: [1.00, 1.00, 512] # summary: 631 layers, 25372160 parameters, 25372144 gradients, 87.6 GFLOPs
  x: [1.00, 1.50, 512] # summary: 631 layers, 56966176 parameters, 56966160 gradients, 196.0 GFLOPs

# YOLO11n backbone
backbone:
  # [from, repeats, module, args]
  - [-1, 1, Conv, [64, 3, 2]] # 0-P1/2
  - [-1, 1, Conv, [128, 3, 2]] # 1-P2/4
  - [-1, 2, C3k2, [256, False, 0.25]]
  - [-1, 1, Conv, [256, 3, 2]] # 3-P3/8
  - [-1, 2, C3k2, [512, False, 0.25]]
  - [-1, 1, Conv, [512, 3, 2]] # 5-P4/16
  - [-1, 2, C3k2, [512, True]]
  - [-1, 1, Conv, [1024, 3, 2]] # 7-P5/32
  - [-1, 2, C3k2, [1024, True]]
  - [-1, 1, CBAM, [1024]]
  - [-1, 1, SPPF, [1024, 5]] # 9
  - [-1, 2, C2PSA, [1024]] # 10

# YOLO11n head
head:
  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [[-1, 6], 1, Concat, [1]] # cat backbone P4
  - [-1, 2, C3k2, [512, False]] # 13

  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [[-1, 4], 1, Concat, [1]] # cat backbone P3
  - [-1, 2, C3k2, [256, False]] # 16 (P3/8-small)

  - [-1, 1, Conv, [256, 3, 2]]
  - [[-1, 14], 1, Concat, [1]] # cat head P4
  - [-1, 2, C3k2, [512, False]] # 19 (P4/16-medium)

  - [-1, 1, Conv, [512, 3, 2]]
  - [[-1, 11], 1, Concat, [1]] # cat head P5
  - [-1, 2, C3k2, [1024, True]] # 22 (P5/32-large)

  - [[17, 20, 23], 1, OBB, [nc, 1]] # Detect(P3, P4, P5)

温馨提示:本文只是对yolo11基础上添加模块,如果要对yolo11n/l/m/x进行添加则只需要指定对应的depth_multiple 和 width_multiple


# YOLO11n
depth_multiple: 0.50  # model depth multiple
width_multiple: 0.25  # layer channel multiple
max_channel:1024
 
# YOLO11s
depth_multiple: 0.50  # model depth multiple
width_multiple: 0.50  # layer channel multiple
max_channel:1024
 
# YOLO11m
depth_multiple: 0.50  # model depth multiple
width_multiple: 1.00  # layer channel multiple
max_channel:512
 
# YOLO11l 
depth_multiple: 1.00  # model depth multiple
width_multiple: 1.00  # layer channel multiple
max_channel:512 
 
# YOLO11x
depth_multiple: 1.00  # model depth multiple
width_multiple: 1.50 # layer channel multiple
max_channel:512

2.4 在task.py中进行注册

关键步骤四:在parse_model函数中进行注册,添加CBAM,

 先在task.py导入函数

然后在task.py文件下找到parse_model这个函数,如下图,添加CBAM

        elif m in (ShuffleAttention, ECAAttention,TripletAttention, CBAM,):
            c1, c2 = ch[f], args[0]
            if c2 != nc:
                c2 = make_divisible(min(c2, max_channels) * width, 8)
            args = [c1, *args[1:]]

其他的六种注意力机制在这添加 

2.5 执行程序

关键步骤五: 在ultralytics文件中新建train.py,将model的参数路径设置为yolo11_CBAM.yaml的路径即可

from ultralytics import YOLO
import warnings
warnings.filterwarnings('ignore')
from pathlib import Path
 
if __name__ == '__main__':
 
 
    # 加载模型
    model = YOLO("ultralytics/cfg/11/yolo11.yaml")  # 你要选择的模型yaml文件地址
    # Use the model
    results = model.train(data=r"你的数据集的yaml文件地址",
                          epochs=100, batch=16, imgsz=640, workers=4, name=Path(model.cfg).stem)  # 训练模型

  🚀运行程序,如果出现下面的内容则说明添加成功🚀 

                   from  n    params  module                                       arguments
  0                  -1  1       464  ultralytics.nn.modules.conv.Conv             [3, 16, 3, 2]
  1                  -1  1      4672  ultralytics.nn.modules.conv.Conv             [16, 32, 3, 2]
  2                  -1  1      6640  ultralytics.nn.modules.block.C3k2            [32, 64, 1, False, 0.25]      
  3                  -1  1     36992  ultralytics.nn.modules.conv.Conv             [64, 64, 3, 2]
  4                  -1  1     26080  ultralytics.nn.modules.block.C3k2            [64, 128, 1, False, 0.25]     
  5                  -1  1    147712  ultralytics.nn.modules.conv.Conv             [128, 128, 3, 2]
  6                  -1  1     87040  ultralytics.nn.modules.block.C3k2            [128, 128, 1, True]
  7                  -1  1    295424  ultralytics.nn.modules.conv.Conv             [128, 256, 3, 2]
  8                  -1  1    346112  ultralytics.nn.modules.block.C3k2            [256, 256, 1, True]
  9                  -1  1     65890  ultralytics.nn.modules.conv.CBAM             [256]
 10                  -1  1    164608  ultralytics.nn.modules.block.SPPF            [256, 256, 5]
 11                  -1  1    249728  ultralytics.nn.modules.block.C2PSA           [256, 256, 1]
 12                  -1  1         0  torch.nn.modules.upsampling.Upsample         [None, 2, 'nearest']
 13             [-1, 6]  1         0  ultralytics.nn.modules.conv.Concat           [1]
 14                  -1  1    111296  ultralytics.nn.modules.block.C3k2            [384, 128, 1, False]
 15                  -1  1         0  torch.nn.modules.upsampling.Upsample         [None, 2, 'nearest']
 16             [-1, 4]  1         0  ultralytics.nn.modules.conv.Concat           [1]
 17                  -1  1     32096  ultralytics.nn.modules.block.C3k2            [256, 64, 1, False]
 18                  -1  1     36992  ultralytics.nn.modules.conv.Conv             [64, 64, 3, 2]
 19            [-1, 14]  1         0  ultralytics.nn.modules.conv.Concat           [1]
 20                  -1  1     86720  ultralytics.nn.modules.block.C3k2            [192, 128, 1, False]
 21                  -1  1    147712  ultralytics.nn.modules.conv.Conv             [128, 128, 3, 2]
 22            [-1, 11]  1         0  ultralytics.nn.modules.conv.Concat           [1]
 23                  -1  1    378880  ultralytics.nn.modules.block.C3k2            [384, 256, 1, True]
 24        [17, 20, 23]  1    464912  ultralytics.nn.modules.head.Detect           [80, [64, 128, 256]]
YOLO11_CBAM summary: 327 layers, 2,689,970 parameters, 2,689,954 gradients, 6.7 GFLOPs

3.修改后的网络结构图

4. 完整代码分享

这个后期补充吧~,先按照步骤来即可

5. GFLOPs

关于GFLOPs的计算方式可以查看百面算法工程师 | 卷积基础知识——Convolution

未改进的YOLO11n GFLOPs

改进后的GFLOPs

6. 其他注意力机制

以CBAM为例子,其他的只换代码,步骤不变

1. EffectiveSE

import torch
from torch import nn as nn
from timm.models.layers.create_act import create_act_layer


class EffectiveSE(nn.Module):
    def __init__(self, channels, add_maxpool=False, gate_layer='hard_sigmoid'):
        super(EffectiveSE, self).__init__()
        self.add_maxpool = add_maxpool
        self.fc = nn.Conv2d(channels, channels, kernel_size=1, padding=0)
        self.gate = create_act_layer(gate_layer)

    def forward(self, x):
        x_se = x.mean((2, 3), keepdim=True)
        if self.add_maxpool:
            # experimental codepath, may remove or change
            x_se = 0.5 * x_se + 0.5 * x.amax((2, 3), keepdim=True)
        x_se = self.fc(x_se)
        return x * self.gate(x_se)

2. TripletAttention

class BasicConv(nn.Module):  # https://arxiv.org/pdf/2010.03045.pdf
    def __init__(self, in_planes, out_planes, kernel_size, stride=1, padding=0, dilation=1, groups=1, relu=True,
                 bn=True, bias=False):
        super(BasicConv, self).__init__()
        self.out_channels = out_planes
        self.conv = nn.Conv2d(in_planes, out_planes, kernel_size=kernel_size, stride=stride, padding=padding,
                              dilation=dilation, groups=groups, bias=bias)
        self.bn = nn.BatchNorm2d(out_planes, eps=1e-5, momentum=0.01, affine=True) if bn else None
        self.relu = nn.ReLU() if relu else None

    def forward(self, x):
        x = self.conv(x)
        if self.bn is not None:
            x = self.bn(x)
        if self.relu is not None:
            x = self.relu(x)
        return x


class ZPool(nn.Module):
    def forward(self, x):
        return torch.cat((torch.max(x, 1)[0].unsqueeze(1), torch.mean(x, 1).unsqueeze(1)), dim=1)


class AttentionGate(nn.Module):
    def __init__(self):
        super(AttentionGate, self).__init__()
        kernel_size = 7
        self.compress = ZPool()
        self.conv = BasicConv(2, 1, kernel_size, stride=1, padding=(kernel_size - 1) // 2, relu=False)

    def forward(self, x):
        x_compress = self.compress(x)
        x_out = self.conv(x_compress)
        scale = torch.sigmoid_(x_out)
        return x * scale


class TripletAttention(nn.Module):
    def __init__(self, no_spatial=False):
        super(TripletAttention, self).__init__()
        self.cw = AttentionGate()
        self.hc = AttentionGate()
        self.no_spatial = no_spatial
        if not no_spatial:
            self.hw = AttentionGate()

    def forward(self, x):
        x_perm1 = x.permute(0, 2, 1, 3).contiguous()
        x_out1 = self.cw(x_perm1)
        x_out11 = x_out1.permute(0, 2, 1, 3).contiguous()
        x_perm2 = x.permute(0, 3, 2, 1).contiguous()
        x_out2 = self.hc(x_perm2)
        x_out21 = x_out2.permute(0, 3, 2, 1).contiguous()
        if not self.no_spatial:
            x_out = self.hw(x)
            x_out = 1 / 3 * (x_out + x_out11 + x_out21)
        else:
            x_out = 1 / 2 * (x_out11 + x_out21)
        return x_out

 3. SEAttention

import numpy as np
import torch
from torch import nn
from torch.nn import init


class SEAttention(nn.Module):

    def __init__(self, channel=512, reduction=16):
        super().__init__()
        self.avg_pool = nn.AdaptiveAvgPool2d(1)
        self.fc = nn.Sequential(
            nn.Linear(channel, channel // reduction, bias=False),
            nn.ReLU(inplace=True),
            nn.Linear(channel // reduction, channel, bias=False),
            nn.Sigmoid()
        )

    def init_weights(self):
        for m in self.modules():
            if isinstance(m, nn.Conv2d):
                init.kaiming_normal_(m.weight, mode='fan_out')
                if m.bias is not None:
                    init.constant_(m.bias, 0)
            elif isinstance(m, nn.BatchNorm2d):
                init.constant_(m.weight, 1)
                init.constant_(m.bias, 0)
            elif isinstance(m, nn.Linear):
                init.normal_(m.weight, std=0.001)
                if m.bias is not None:
                    init.constant_(m.bias, 0)

    def forward(self, x):
        b, c, _, _ = x.size()
        y = self.avg_pool(x).view(b, c)
        y = self.fc(y).view(b, c, 1, 1)
        return x * y.expand_as(x)

4. ECAAttention

class ECAAttention(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, k_size=3):
        super(ECAAttention, 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()

    def forward(self, x):
        # feature descriptor on the global spatial information
        y = self.avg_pool(x)
        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)

5.ShuffleAttention

import torch
from torch import nn
from torch.nn import init
from torch.nn.parameter import Parameter


class ShuffleAttention(nn.Module):

    def __init__(self, channel=512, reduction=16, G=8):
        super().__init__()
        self.G = G
        self.channel = channel
        self.avg_pool = nn.AdaptiveAvgPool2d(1)
        self.gn = nn.GroupNorm(channel // (2 * G), channel // (2 * G))
        self.cweight = Parameter(torch.zeros(1, channel // (2 * G), 1, 1))
        self.cbias = Parameter(torch.ones(1, channel // (2 * G), 1, 1))
        self.sweight = Parameter(torch.zeros(1, channel // (2 * G), 1, 1))
        self.sbias = Parameter(torch.ones(1, channel // (2 * G), 1, 1))
        self.sigmoid = nn.Sigmoid()

    def init_weights(self):
        for m in self.modules():
            if isinstance(m, nn.Conv2d):
                init.kaiming_normal_(m.weight, mode='fan_out')
                if m.bias is not None:
                    init.constant_(m.bias, 0)
            elif isinstance(m, nn.BatchNorm2d):
                init.constant_(m.weight, 1)
                init.constant_(m.bias, 0)
            elif isinstance(m, nn.Linear):
                init.normal_(m.weight, std=0.001)
                if m.bias is not None:
                    init.constant_(m.bias, 0)

    @staticmethod
    def channel_shuffle(x, groups):
        b, c, h, w = x.shape
        x = x.reshape(b, groups, -1, h, w)
        x = x.permute(0, 2, 1, 3, 4)

        # flatten
        x = x.reshape(b, -1, h, w)

        return x

    def forward(self, x):
        b, c, h, w = x.size()
        # group into subfeatures
        x = x.view(b * self.G, -1, h, w)  # bs*G,c//G,h,w

        # channel_split
        x_0, x_1 = x.chunk(2, dim=1)  # bs*G,c//(2*G),h,w

        # channel attention
        x_channel = self.avg_pool(x_0)  # bs*G,c//(2*G),1,1
        x_channel = self.cweight * x_channel + self.cbias  # bs*G,c//(2*G),1,1
        x_channel = x_0 * self.sigmoid(x_channel)

        # spatial attention
        x_spatial = self.gn(x_1)  # bs*G,c//(2*G),h,w
        x_spatial = self.sweight * x_spatial + self.sbias  # bs*G,c//(2*G),h,w
        x_spatial = x_1 * self.sigmoid(x_spatial)  # bs*G,c//(2*G),h,w

        # concatenate along channel axis
        out = torch.cat([x_channel, x_spatial], dim=1)  # bs*G,c//G,h,w
        out = out.contiguous().view(b, -1, h, w)

        # channel shuffle
        out = self.channel_shuffle(out, 2)
        return out

6.GatherExcite

import math, torch
from torch import nn as nn
import torch.nn.functional as F

from timm.models.layers.create_act import create_act_layer, get_act_layer
from timm.models.layers.create_conv2d import create_conv2d
from timm.models.layers.helpers import make_divisible
from timm.models.layers.mlp import ConvMlp


class GatherExcite(nn.Module):
    def __init__(
            self, channels, feat_size=None, extra_params=False, extent=0, use_mlp=True,
            rd_ratio=1. / 16, rd_channels=None, rd_divisor=1, add_maxpool=False,
            act_layer=nn.ReLU, norm_layer=nn.BatchNorm2d, gate_layer='sigmoid'):
        super(GatherExcite, self).__init__()
        self.add_maxpool = add_maxpool
        act_layer = get_act_layer(act_layer)
        self.extent = extent
        if extra_params:
            self.gather = nn.Sequential()
            if extent == 0:
                assert feat_size is not None, 'spatial feature size must be specified for global extent w/ params'
                self.gather.add_module(
                    'conv1', create_conv2d(channels, channels, kernel_size=feat_size, stride=1, depthwise=True))
                if norm_layer:
                    self.gather.add_module(f'norm1', nn.BatchNorm2d(channels))
            else:
                assert extent % 2 == 0
                num_conv = int(math.log2(extent))
                for i in range(num_conv):
                    self.gather.add_module(
                        f'conv{i + 1}',
                        create_conv2d(channels, channels, kernel_size=3, stride=2, depthwise=True))
                    if norm_layer:
                        self.gather.add_module(f'norm{i + 1}', nn.BatchNorm2d(channels))
                    if i != num_conv - 1:
                        self.gather.add_module(f'act{i + 1}', act_layer(inplace=True))
        else:
            self.gather = None
            if self.extent == 0:
                self.gk = 0
                self.gs = 0
            else:
                assert extent % 2 == 0
                self.gk = self.extent * 2 - 1
                self.gs = self.extent

        if not rd_channels:
            rd_channels = make_divisible(channels * rd_ratio, rd_divisor, round_limit=0.)
        self.mlp = ConvMlp(channels, rd_channels, act_layer=act_layer) if use_mlp else nn.Identity()
        self.gate = create_act_layer(gate_layer)

    def forward(self, x):
        size = x.shape[-2:]
        if self.gather is not None:
            x_ge = self.gather(x)
        else:
            if self.extent == 0:
                # global extent
                x_ge = x.mean(dim=(2, 3), keepdims=True)
                if self.add_maxpool:
                    # experimental codepath, may remove or change
                    x_ge = 0.5 * x_ge + 0.5 * x.amax((2, 3), keepdim=True)
            else:
                x_ge = F.avg_pool2d(
                    x, kernel_size=self.gk, stride=self.gs, padding=self.gk // 2, count_include_pad=False)
                if self.add_maxpool:
                    # experimental codepath, may remove or change
                    x_ge = 0.5 * x_ge + 0.5 * F.max_pool2d(x, kernel_size=self.gk, stride=self.gs, padding=self.gk // 2)
        x_ge = self.mlp(x_ge)
        if x_ge.shape[-1] != 1 or x_ge.shape[-2] != 1:
            x_ge = F.interpolate(x_ge, size=size)
        return x * self.gate(x_ge)

7.GlobalContext

import torch
from torch import nn as nn
import torch.nn.functional as F
from timm.models.layers.create_act import create_act_layer, get_act_layer
from timm.models.layers.helpers import make_divisible
from timm.models.layers.mlp import ConvMlp
from timm.models.layers.norm import LayerNorm2d


class GlobalContext(nn.Module):

    def __init__(self, channels, use_attn=True, fuse_add=False, fuse_scale=True, init_last_zero=False,
                 rd_ratio=1. / 8, rd_channels=None, rd_divisor=1, act_layer=nn.ReLU, gate_layer='sigmoid'):
        super(GlobalContext, self).__init__()
        act_layer = get_act_layer(act_layer)

        self.conv_attn = nn.Conv2d(channels, 1, kernel_size=1, bias=True) if use_attn else None

        if rd_channels is None:
            rd_channels = make_divisible(channels * rd_ratio, rd_divisor, round_limit=0.)
        if fuse_add:
            self.mlp_add = ConvMlp(channels, rd_channels, act_layer=act_layer, norm_layer=LayerNorm2d)
        else:
            self.mlp_add = None
        if fuse_scale:
            self.mlp_scale = ConvMlp(channels, rd_channels, act_layer=act_layer, norm_layer=LayerNorm2d)
        else:
            self.mlp_scale = None

        self.gate = create_act_layer(gate_layer)
        self.init_last_zero = init_last_zero
        self.reset_parameters()

    def reset_parameters(self):
        if self.conv_attn is not None:
            nn.init.kaiming_normal_(self.conv_attn.weight, mode='fan_in', nonlinearity='relu')
        if self.mlp_add is not None:
            nn.init.zeros_(self.mlp_add.fc2.weight)

    def forward(self, x):
        B, C, H, W = x.shape

        if self.conv_attn is not None:
            attn = self.conv_attn(x).reshape(B, 1, H * W)  # (B, 1, H * W)
            attn = F.softmax(attn, dim=-1).unsqueeze(3)  # (B, 1, H * W, 1)
            context = x.reshape(B, C, H * W).unsqueeze(1) @ attn
            context = context.view(B, C, 1, 1)
        else:
            context = x.mean(dim=(2, 3), keepdim=True)

        if self.mlp_scale is not None:
            mlp_x = self.mlp_scale(context)
            x = x * self.gate(mlp_x)
        if self.mlp_add is not None:
            mlp_x = self.mlp_add(context)
            x = x + mlp_x

        return x

8.ResBlock_CBAM

class ResBlock_CBAM(nn.Module):
    def __init__(self, in_places, places, stride=1, downsampling=False, expansion=1):
        super(ResBlock_CBAM, self).__init__()
        self.expansion = expansion
        self.downsampling = downsampling

        self.bottleneck = nn.Sequential(
            nn.Conv2d(in_channels=in_places, out_channels=places, kernel_size=1, stride=1, bias=False),
            nn.BatchNorm2d(places),
            nn.LeakyReLU(0.1, inplace=True),
            nn.Conv2d(in_channels=places, out_channels=places, kernel_size=3, stride=stride, padding=1, bias=False),
            nn.BatchNorm2d(places),
            nn.LeakyReLU(0.1, inplace=True),
            nn.Conv2d(in_channels=places, out_channels=places * self.expansion, kernel_size=1, stride=1,
                      bias=False),
            nn.BatchNorm2d(places * self.expansion),
        )
        # self.cbam = CBAM(c1=places * self.expansion, c2=places * self.expansion, )
        self.cbam = CBAM(c1=places * self.expansion)

        if self.downsampling:
            self.downsample = nn.Sequential(
                nn.Conv2d(in_channels=in_places, out_channels=places * self.expansion, kernel_size=1, stride=stride,
                          bias=False),
                nn.BatchNorm2d(places * self.expansion)
            )
        self.relu = nn.ReLU(inplace=True)

    def forward(self, x):
        residual = x
        out = self.bottleneck(x)
        out = self.cbam(out)
        if self.downsampling:
            residual = self.downsample(x)

        out += residual
        out = self.relu(out)
        return out

7. 进阶

可以与其他的注意力机制或者损失函数等结合,进一步提升检测效果

8.总结

通过以上的改进方法,我们成功提升了模型的表现。这只是一个开始,未来还有更多优化和技术深挖的空间。在这里,我想隆重向大家推荐我的专栏——<专栏地址:YOLO11入门 + 改进涨点——点击即可跳转 欢迎订阅>。这个专栏专注于前沿的深度学习技术,特别是目标检测领域的最新进展,不仅包含对YOLO11的深入解析和改进策略,还会定期更新来自各大顶会(如CVPR、NeurIPS等)的论文复现和实战分享。

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原文地址:https://blog.csdn.net/m0_67647321/article/details/142964068

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