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如何将yolov5中的PANet层改为BiFPN详析

作者:m0_56247038

现在yolov5的neck用的是PANet,在efficient论文中提出了BiFPN结构,还有更加不错的性能,下面这篇文章主要给大家介绍了关于如何将yolov5中的PANet层改为BiFPN的相关资料,需要的朋友可以参考下

本文以YOLOv5-6.1版本为例

一、Add

1.在common.py后加入如下代码

# 结合BiFPN 设置可学习参数 学习不同分支的权重
# 两个分支add操作
class BiFPN_Add2(nn.Module):
    def __init__(self, c1, c2):
        super(BiFPN_Add2, self).__init__()
        # 设置可学习参数 nn.Parameter的作用是:将一个不可训练的类型Tensor转换成可以训练的类型parameter
        # 并且会向宿主模型注册该参数 成为其一部分 即model.parameters()会包含这个parameter
        # 从而在参数优化的时候可以自动一起优化
        self.w = nn.Parameter(torch.ones(2, dtype=torch.float32), requires_grad=True)
        self.epsilon = 0.0001
        self.conv = nn.Conv2d(c1, c2, kernel_size=1, stride=1, padding=0)
        self.silu = nn.SiLU()
 
    def forward(self, x):
        w = self.w
        weight = w / (torch.sum(w, dim=0) + self.epsilon)
        return self.conv(self.silu(weight[0] * x[0] + weight[1] * x[1]))
 
 
# 三个分支add操作
class BiFPN_Add3(nn.Module):
    def __init__(self, c1, c2):
        super(BiFPN_Add3, self).__init__()
        self.w = nn.Parameter(torch.ones(3, dtype=torch.float32), requires_grad=True)
        self.epsilon = 0.0001
        self.conv = nn.Conv2d(c1, c2, kernel_size=1, stride=1, padding=0)
        self.silu = nn.SiLU()
 
    def forward(self, x):
        w = self.w
        weight = w / (torch.sum(w, dim=0) + self.epsilon)  # 将权重进行归一化
        # Fast normalized fusion
        return self.conv(self.silu(weight[0] * x[0] + weight[1] * x[1] + weight[2] * x[2]))

2.yolov5s.yaml进行修改

# YOLOv5 🚀 by Ultralytics, GPL-3.0 license
 
# Parameters
nc: 80  # number of classes
depth_multiple: 0.33  # model depth multiple
width_multiple: 0.50  # layer channel multiple
anchors:
  - [10,13, 16,30, 33,23]  # P3/8
  - [30,61, 62,45, 59,119]  # P4/16
  - [116,90, 156,198, 373,326]  # P5/32
 
# YOLOv5 v6.0 backbone
backbone:
  # [from, number, module, args]
  [[-1, 1, Conv, [64, 6, 2, 2]],  # 0-P1/2
   [-1, 1, Conv, [128, 3, 2]],  # 1-P2/4
   [-1, 3, C3, [128]],
   [-1, 1, Conv, [256, 3, 2]],  # 3-P3/8
   [-1, 6, C3, [256]],
   [-1, 1, Conv, [512, 3, 2]],  # 5-P4/16
   [-1, 9, C3, [512]],
   [-1, 1, Conv, [1024, 3, 2]],  # 7-P5/32
   [-1, 3, C3, [1024]],
   [-1, 1, SPPF, [1024, 5]],  # 9
  ]
 
# YOLOv5 v6.0 BiFPN head
head:
  [[-1, 1, Conv, [512, 1, 1]],
   [-1, 1, nn.Upsample, [None, 2, 'nearest']],
   [[-1, 6], 1, BiFPN_Add2, [256, 256]],  # cat backbone P4
   [-1, 3, C3, [512, False]],  # 13
 
   [-1, 1, Conv, [256, 1, 1]],
   [-1, 1, nn.Upsample, [None, 2, 'nearest']],
   [[-1, 4], 1, BiFPN_Add2, [128, 128]],  # cat backbone P3
   [-1, 3, C3, [256, False]],  # 17 (P3/8-small)
 
   [-1, 1, Conv, [512, 3, 2]],  # 为了BiFPN正确add,调整channel数
   [[-1, 13, 6], 1, BiFPN_Add3, [256, 256]],  # cat P4 <--- BiFPN change 注意v5s通道数是默认参数的一半
   [-1, 3, C3, [512, False]],  # 20 (P4/16-medium)
 
   [-1, 1, Conv, [512, 3, 2]],
   [[-1, 10], 1, BiFPN_Add2, [256, 256]],  # cat head P5
   [-1, 3, C3, [1024, False]],  # 23 (P5/32-large)
 
   [[17, 20, 23], 1, Detect, [nc, anchors]],  # Detect(P3, P4, P5)
  ]

3.修改yolo.py,在parse_model函数中找到elif m is Concat:语句,在其后面加上BiFPN_Add相关语句:

# 添加bifpn_add结构
elif m in [BiFPN_Add2, BiFPN_Add3]:
    c2 = max([ch[x] for x in f])

4.修改train.py,向优化器中添加BiFPN的权重参数

BiFPN_Add2BiFPN_Add3函数中定义的w参数,加入g1

 # BiFPN_Concat
        elif isinstance(v, BiFPN_Add2) and hasattr(v, 'w') and isinstance(v.w, nn.Parameter):
            g1.append(v.w)
        elif isinstance(v, BiFPN_Add3) and hasattr(v, 'w') and isinstance(v.w, nn.Parameter):
            g1.append(v.w)
 

然后导入一下这两个包

二、Concat

1.在common.py后加入如下代码

# 结合BiFPN 设置可学习参数 学习不同分支的权重
# 两个分支concat操作
class BiFPN_Concat2(nn.Module):
    def __init__(self, dimension=1):
        super(BiFPN_Concat2, self).__init__()
        self.d = dimension
        self.w = nn.Parameter(torch.ones(2, dtype=torch.float32), requires_grad=True)
        self.epsilon = 0.0001
 
    def forward(self, x):
        w = self.w
        weight = w / (torch.sum(w, dim=0) + self.epsilon)  # 将权重进行归一化
        # Fast normalized fusion
        x = [weight[0] * x[0], weight[1] * x[1]]
        return torch.cat(x, self.d)
 
 
# 三个分支concat操作
class BiFPN_Concat3(nn.Module):
    def __init__(self, dimension=1):
        super(BiFPN_Concat3, self).__init__()
        self.d = dimension
        # 设置可学习参数 nn.Parameter的作用是:将一个不可训练的类型Tensor转换成可以训练的类型parameter
        # 并且会向宿主模型注册该参数 成为其一部分 即model.parameters()会包含这个parameter
        # 从而在参数优化的时候可以自动一起优化
        self.w = nn.Parameter(torch.ones(3, dtype=torch.float32), requires_grad=True)
        self.epsilon = 0.0001
 
    def forward(self, x):
        w = self.w
        weight = w / (torch.sum(w, dim=0) + self.epsilon)  # 将权重进行归一化
        # Fast normalized fusion
        x = [weight[0] * x[0], weight[1] * x[1], weight[2] * x[2]]
        return torch.cat(x, self.d)

2.yolov5s.yaml进行修改 

# YOLOv5 🚀 by Ultralytics, GPL-3.0 license
 
# Parameters
nc: 80  # number of classes
depth_multiple: 0.33  # model depth multiple
width_multiple: 0.50  # layer channel multiple
anchors:
  - [10,13, 16,30, 33,23]  # P3/8
  - [30,61, 62,45, 59,119]  # P4/16
  - [116,90, 156,198, 373,326]  # P5/32
 
# YOLOv5 v6.0 backbone
backbone:
  # [from, number, module, args]
  [[-1, 1, Conv, [64, 6, 2, 2]],  # 0-P1/2
   [-1, 1, Conv, [128, 3, 2]],  # 1-P2/4
   [-1, 3, C3, [128]],
   [-1, 1, Conv, [256, 3, 2]],  # 3-P3/8
   [-1, 6, C3, [256]],
   [-1, 1, Conv, [512, 3, 2]],  # 5-P4/16
   [-1, 9, C3, [512]],
   [-1, 1, Conv, [1024, 3, 2]],  # 7-P5/32
   [-1, 3, C3, [1024]],
   [-1, 1, SPPF, [1024, 5]],  # 9
  ]
 
# YOLOv5 v6.0 BiFPN head
head:
  [[-1, 1, Conv, [512, 1, 1]],
   [-1, 1, nn.Upsample, [None, 2, 'nearest']],
   [[-1, 6], 1, BiFPN_Concat2, [1]],  # cat backbone P4 <--- BiFPN change
   [-1, 3, C3, [512, False]],  # 13
 
   [-1, 1, Conv, [256, 1, 1]],
   [-1, 1, nn.Upsample, [None, 2, 'nearest']],
   [[-1, 4], 1, BiFPN_Concat2, [1]],  # cat backbone P3 <--- BiFPN change
   [-1, 3, C3, [256, False]],  # 17 (P3/8-small)
 
   [-1, 1, Conv, [256, 3, 2]],
   [[-1, 14, 6], 1, BiFPN_Concat3, [1]],  # cat P4 <--- BiFPN change
   [-1, 3, C3, [512, False]],  # 20 (P4/16-medium)
 
   [-1, 1, Conv, [512, 3, 2]],
   [[-1, 10], 1, BiFPN_Concat2, [1]],  # cat head P5 <--- BiFPN change
   [-1, 3, C3, [1024, False]],  # 23 (P5/32-large)
 
   [[17, 20, 23], 1, Detect, [nc, anchors]],  # Detect(P3, P4, P5)
  ]

3.修改yolo.py,在parse_model函数中找到elif m is Concat:语句,在其后面加上BiFPN_Concat相关语句: 

# 添加bifpn_concat结构
elif m in [Concat, BiFPN_Concat2, BiFPN_Concat3]:
    c2 = sum(ch[x] for x in f)

4.修改train.py,向优化器中添加BiFPN的权重参数

添加复方式同上(Add)

# BiFPN_Concat
        elif isinstance(v, BiFPN_Concat2) and hasattr(v, 'w') and isinstance(v.w, nn.Parameter):
            g1.append(v.w)
        elif isinstance(v, BiFPN_Concat3) and hasattr(v, 'w') and isinstance(v.w, nn.Parameter):
            g1.append(v.w)

至此,大功告成~~~

reference:

【YOLOv5-6.x】设置可学习权重结合BiFPN(Add操作)

【YOLOv5-6.x】设置可学习权重结合BiFPN(Concat操作)

总结

到此这篇关于如何将yolov5中的PANet层改为BiFPN的文章就介绍到这了,更多相关yolov5 PANet层改BiFPN内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家!

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