一、导言
SimSPPF(Simplified Spatial Pyramid Pooling with Fixed-size kernel)模块是在YOLOv6架构中引入的一个关键组件,它旨在优化原始SPPF(Spatial Pyramid Pooling Fixed-size)模块的效率。以下是SimSPPF的一些优点和可能存在的缺点:
优点:
-  效率提升: SimSPPF通过简化原有的SPPF结构,使用固定大小的池化核(通常是5x5),从而显著减少了计算量和内存消耗,这使得模型在推断阶段运行得更快。 
-  感受野扩大: 尽管使用了较小的池化核,SimSPPF仍然能够有效地捕获多尺度特征,因为其设计允许在网络中整合不同层级的信息,这对于物体检测任务来说非常重要。 
-  易于实现: 由于其设计上的简化,SimSPPF比原始的SPPF更容易在不同的硬件平台上实现和优化。 
-  适应性: 在YOLOv6的不同变体中(如YOLOv6-N/S/M),SimSPPF可以根据模型的大小和特定需求进行调整,例如在较小的模型中使用SimCSPSPPF以进一步加速,而在较大的模型中使用SimSPPF以保持良好的精度。 
缺点:
-  可能的信息损失: 通过使用固定大小的池化核,SimSPPF可能会牺牲一些大尺度的特征信息,这是由于较大尺寸的池化核能够捕捉到更大范围内的上下文信息。 
-  精度折衷: 虽然效率提高了,但这种简化可能会影响模型在某些场景下的检测精度,特别是对于那些需要非常精细的多尺度分析的情况。 
-  灵活性降低: 固定大小的池化核限制了SimSPPF的灵活性,因为它不能像可变大小的SPPF那样自适应地调整其感受野的大小。 
-  泛化能力: 理论上讲,固定的池化核可能会限制模型处理各种尺度输入的能力,尽管实践中这种影响可能被其他网络组件所弥补。 
总体而言,SimSPPF模块是YOLOv6设计中为了平衡速度和精度而做出的一种选择,它通过牺牲一定的复杂性和理论上的精度,换取了实际应用中的高效率和快速响应。
二、准备工作
首先在YOLOv5/v7的models文件夹下新建文件morepooling.py,导入如下代码
import warningsfrom models.common import *
# simsppf
# yolov6
class SimConv(nn.Module):'''Normal Conv with ReLU activation'''def __init__(self, in_channels, out_channels, kernel_size, stride, groups=1, bias=False):super().__init__()padding = kernel_size // 2self.conv = nn.Conv2d(in_channels,out_channels,kernel_size=kernel_size,stride=stride,padding=padding,groups=groups,bias=bias,)self.bn = nn.BatchNorm2d(out_channels)self.act = nn.ReLU()def forward(self, x):return self.act(self.bn(self.conv(x)))def forward_fuse(self, x):return self.act(self.conv(x))class SimSPPF(nn.Module):'''Simplified SPPF with ReLU activation'''def __init__(self, in_channels, out_channels, kernel_size=5):super().__init__()c_ = in_channels // 2  # hidden channelsself.cv1 = SimConv(in_channels, c_, 1, 1)self.cv2 = SimConv(c_ * 4, out_channels, 1, 1)self.m = nn.MaxPool2d(kernel_size=kernel_size, stride=1, padding=kernel_size // 2)def forward(self, x):x = self.cv1(x)with warnings.catch_warnings():warnings.simplefilter('ignore')y1 = self.m(x)y2 = self.m(y1)return self.cv2(torch.cat([x, y1, y2, self.m(y2)], 1))
其次在在YOLOv5/v7项目文件下的models/yolo.py中在文件首部添加代码
from models.morepooling import *并搜索def parse_model(d, ch)
定位到如下行添加以下代码
SimSPPF,
三、YOLOv7-tiny改进工作
完成二后,在YOLOv7项目文件下的models文件夹下创建新的文件yolov7-tiny-simsppf.yaml,导入如下代码。
# parameters
nc: 80  # number of classes
depth_multiple: 1.0  # model depth multiple
width_multiple: 1.0  # layer channel multiple# anchors
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# yolov7-tiny backbone
backbone:# [from, number, module, args] c2, k=1, s=1, p=None, g=1, act=True[[-1, 1, Conv, [32, 3, 2, None, 1, nn.LeakyReLU(0.1)]],  # 0-P1/2[-1, 1, Conv, [64, 3, 2, None, 1, nn.LeakyReLU(0.1)]],  # 1-P2/4[-1, 1, Conv, [32, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-2, 1, Conv, [32, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [32, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [32, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[[-1, -2, -3, -4], 1, Concat, [1]],[-1, 1, Conv, [64, 1, 1, None, 1, nn.LeakyReLU(0.1)]],  # 7[-1, 1, MP, []],  # 8-P3/8[-1, 1, Conv, [64, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-2, 1, Conv, [64, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [64, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [64, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[[-1, -2, -3, -4], 1, Concat, [1]],[-1, 1, Conv, [128, 1, 1, None, 1, nn.LeakyReLU(0.1)]],  # 14[-1, 1, MP, []],  # 15-P4/16[-1, 1, Conv, [128, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-2, 1, Conv, [128, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [128, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [128, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[[-1, -2, -3, -4], 1, Concat, [1]],[-1, 1, Conv, [256, 1, 1, None, 1, nn.LeakyReLU(0.1)]],  # 21[-1, 1, MP, []],  # 22-P5/32[-1, 1, Conv, [256, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-2, 1, Conv, [256, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [256, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [256, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[[-1, -2, -3, -4], 1, Concat, [1]],[-1, 1, Conv, [512, 1, 1, None, 1, nn.LeakyReLU(0.1)]],  # 28]# yolov7-tiny head
head:[[-1, 1, SimSPPF, [256]], # 29[-1, 1, Conv, [128, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, nn.Upsample, [None, 2, 'nearest']],[21, 1, Conv, [128, 1, 1, None, 1, nn.LeakyReLU(0.1)]], # route backbone P4[[-1, -2], 1, Concat, [1]],[-1, 1, Conv, [64, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-2, 1, Conv, [64, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [64, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [64, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[[-1, -2, -3, -4], 1, Concat, [1]],[-1, 1, Conv, [128, 1, 1, None, 1, nn.LeakyReLU(0.1)]],  # 39[-1, 1, Conv, [64, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, nn.Upsample, [None, 2, 'nearest']],[14, 1, Conv, [64, 1, 1, None, 1, nn.LeakyReLU(0.1)]], # route backbone P3[[-1, -2], 1, Concat, [1]],[-1, 1, Conv, [32, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-2, 1, Conv, [32, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [32, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [32, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[[-1, -2, -3, -4], 1, Concat, [1]],[-1, 1, Conv, [64, 1, 1, None, 1, nn.LeakyReLU(0.1)]],  # 49[-1, 1, Conv, [128, 3, 2, None, 1, nn.LeakyReLU(0.1)]],[[-1, 39], 1, Concat, [1]],[-1, 1, Conv, [64, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-2, 1, Conv, [64, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [64, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [64, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[[-1, -2, -3, -4], 1, Concat, [1]],[-1, 1, Conv, [128, 1, 1, None, 1, nn.LeakyReLU(0.1)]],  # 57[-1, 1, Conv, [256, 3, 2, None, 1, nn.LeakyReLU(0.1)]],[[-1, 29], 1, Concat, [1]],[-1, 1, Conv, [128, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-2, 1, Conv, [128, 1, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [128, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[-1, 1, Conv, [128, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[[-1, -2, -3, -4], 1, Concat, [1]],[-1, 1, Conv, [256, 1, 1, None, 1, nn.LeakyReLU(0.1)]],  # 65[49, 1, Conv, [128, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[57, 1, Conv, [256, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[65, 1, Conv, [512, 3, 1, None, 1, nn.LeakyReLU(0.1)]],[[66, 67, 68], 1, IDetect, [nc, anchors]],   # Detect(P3, P4, P5)]
from  n    params  module                                  arguments                     0                -1  1       928  models.common.Conv                      [3, 32, 3, 2, None, 1, LeakyReLU(negative_slope=0.1)]1                -1  1     18560  models.common.Conv                      [32, 64, 3, 2, None, 1, LeakyReLU(negative_slope=0.1)]2                -1  1      2112  models.common.Conv                      [64, 32, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]3                -2  1      2112  models.common.Conv                      [64, 32, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]4                -1  1      9280  models.common.Conv                      [32, 32, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]5                -1  1      9280  models.common.Conv                      [32, 32, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]6  [-1, -2, -3, -4]  1         0  models.common.Concat                    [1]                           7                -1  1      8320  models.common.Conv                      [128, 64, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]8                -1  1         0  models.common.MP                        []                            9                -1  1      4224  models.common.Conv                      [64, 64, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]10                -2  1      4224  models.common.Conv                      [64, 64, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]11                -1  1     36992  models.common.Conv                      [64, 64, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]12                -1  1     36992  models.common.Conv                      [64, 64, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]13  [-1, -2, -3, -4]  1         0  models.common.Concat                    [1]                           14                -1  1     33024  models.common.Conv                      [256, 128, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]15                -1  1         0  models.common.MP                        []                            16                -1  1     16640  models.common.Conv                      [128, 128, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]17                -2  1     16640  models.common.Conv                      [128, 128, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]18                -1  1    147712  models.common.Conv                      [128, 128, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]19                -1  1    147712  models.common.Conv                      [128, 128, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]20  [-1, -2, -3, -4]  1         0  models.common.Concat                    [1]                           21                -1  1    131584  models.common.Conv                      [512, 256, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]22                -1  1         0  models.common.MP                        []                            23                -1  1     66048  models.common.Conv                      [256, 256, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]24                -2  1     66048  models.common.Conv                      [256, 256, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]25                -1  1    590336  models.common.Conv                      [256, 256, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]26                -1  1    590336  models.common.Conv                      [256, 256, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]27  [-1, -2, -3, -4]  1         0  models.common.Concat                    [1]                           28                -1  1    525312  models.common.Conv                      [1024, 512, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]29                -1  1    394240  models.morepooling.SimSPPF              [512, 256]                    30                -1  1     33024  models.common.Conv                      [256, 128, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]31                -1  1         0  torch.nn.modules.upsampling.Upsample    [None, 2, 'nearest']          32                21  1     33024  models.common.Conv                      [256, 128, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]33          [-1, -2]  1         0  models.common.Concat                    [1]                           34                -1  1     16512  models.common.Conv                      [256, 64, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]35                -2  1     16512  models.common.Conv                      [256, 64, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]36                -1  1     36992  models.common.Conv                      [64, 64, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]37                -1  1     36992  models.common.Conv                      [64, 64, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]38  [-1, -2, -3, -4]  1         0  models.common.Concat                    [1]                           39                -1  1     33024  models.common.Conv                      [256, 128, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]40                -1  1      8320  models.common.Conv                      [128, 64, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]41                -1  1         0  torch.nn.modules.upsampling.Upsample    [None, 2, 'nearest']          42                14  1      8320  models.common.Conv                      [128, 64, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]43          [-1, -2]  1         0  models.common.Concat                    [1]                           44                -1  1      4160  models.common.Conv                      [128, 32, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]45                -2  1      4160  models.common.Conv                      [128, 32, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]46                -1  1      9280  models.common.Conv                      [32, 32, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]47                -1  1      9280  models.common.Conv                      [32, 32, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]48  [-1, -2, -3, -4]  1         0  models.common.Concat                    [1]                           49                -1  1      8320  models.common.Conv                      [128, 64, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]50                -1  1     73984  models.common.Conv                      [64, 128, 3, 2, None, 1, LeakyReLU(negative_slope=0.1)]51          [-1, 39]  1         0  models.common.Concat                    [1]                           52                -1  1     16512  models.common.Conv                      [256, 64, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]53                -2  1     16512  models.common.Conv                      [256, 64, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]54                -1  1     36992  models.common.Conv                      [64, 64, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]55                -1  1     36992  models.common.Conv                      [64, 64, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]56  [-1, -2, -3, -4]  1         0  models.common.Concat                    [1]                           57                -1  1     33024  models.common.Conv                      [256, 128, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]58                -1  1    295424  models.common.Conv                      [128, 256, 3, 2, None, 1, LeakyReLU(negative_slope=0.1)]59          [-1, 29]  1         0  models.common.Concat                    [1]                           60                -1  1     65792  models.common.Conv                      [512, 128, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]61                -2  1     65792  models.common.Conv                      [512, 128, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]62                -1  1    147712  models.common.Conv                      [128, 128, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]63                -1  1    147712  models.common.Conv                      [128, 128, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]64  [-1, -2, -3, -4]  1         0  models.common.Concat                    [1]                           65                -1  1    131584  models.common.Conv                      [512, 256, 1, 1, None, 1, LeakyReLU(negative_slope=0.1)]66                49  1     73984  models.common.Conv                      [64, 128, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]67                57  1    295424  models.common.Conv                      [128, 256, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]68                65  1   1180672  models.common.Conv                      [256, 512, 3, 1, None, 1, LeakyReLU(negative_slope=0.1)]69      [66, 67, 68]  1     17132  models.yolo.IDetect                     [1, [[10, 13, 16, 30, 33, 23], [30, 61, 62, 45, 59, 119], [116, 90, 156, 198, 373, 326]], [128, 256, 512]]Model Summary: 249 layers, 5751820 parameters, 5751820 gradients, 13.0 GFLOPS运行后若打印出如上文本代表改进成功。
四、YOLOv5s改进工作
完成二后,在YOLOv5项目文件下的models文件夹下创建新的文件yolov5s-simsppf.yaml,导入如下代码。
# Parameters
nc: 1  # 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, SimSPPF, [1024]],]# YOLOv5 v6.0 head
head:[[-1, 1, Conv, [512, 1, 1]],[-1, 1, nn.Upsample, [None, 2, 'nearest']],[[-1, 6], 1, Concat, [1]],  # 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, Concat, [1]],  # cat backbone P3[-1, 3, C3, [256, False]],  # 17 (P3/8-small)[-1, 1, Conv, [256, 3, 2]],[[-1, 14], 1, Concat, [1]],  # cat head P4[-1, 3, C3, [512, False]],  # 20 (P4/16-medium)[-1, 1, Conv, [512, 3, 2]],[[-1, 10], 1, Concat, [1]],  # cat head P5[-1, 3, C3, [1024, False]],  # 23 (P5/32-large)[[17, 20, 23], 1, Detect, [nc, anchors]],  # Detect(P3, P4, P5)]
from  n    params  module                                  arguments                     0                -1  1      3520  models.common.Conv                      [3, 32, 6, 2, 2]              1                -1  1     18560  models.common.Conv                      [32, 64, 3, 2]                2                -1  1     18816  models.common.C3                        [64, 64, 1]                   3                -1  1     73984  models.common.Conv                      [64, 128, 3, 2]               4                -1  2    115712  models.common.C3                        [128, 128, 2]                 5                -1  1    295424  models.common.Conv                      [128, 256, 3, 2]              6                -1  3    625152  models.common.C3                        [256, 256, 3]                 7                -1  1   1180672  models.common.Conv                      [256, 512, 3, 2]              8                -1  1   1182720  models.common.C3                        [512, 512, 1]                 9                -1  1    656896  models.morepooling.SimSPPF              [512, 512, 5]                 10                -1  1    131584  models.common.Conv                      [512, 256, 1, 1]              11                -1  1         0  torch.nn.modules.upsampling.Upsample    [None, 2, 'nearest']          12           [-1, 6]  1         0  models.common.Concat                    [1]                           13                -1  1    361984  models.common.C3                        [512, 256, 1, False]          14                -1  1     33024  models.common.Conv                      [256, 128, 1, 1]              15                -1  1         0  torch.nn.modules.upsampling.Upsample    [None, 2, 'nearest']          16           [-1, 4]  1         0  models.common.Concat                    [1]                           17                -1  1     90880  models.common.C3                        [256, 128, 1, False]          18                -1  1    147712  models.common.Conv                      [128, 128, 3, 2]              19          [-1, 14]  1         0  models.common.Concat                    [1]                           20                -1  1    296448  models.common.C3                        [256, 256, 1, False]          21                -1  1    590336  models.common.Conv                      [256, 256, 3, 2]              22          [-1, 10]  1         0  models.common.Concat                    [1]                           23                -1  1   1182720  models.common.C3                        [512, 512, 1, False]          24      [17, 20, 23]  1     16182  models.yolo.Detect                      [1, [[10, 13, 16, 30, 33, 23], [30, 61, 62, 45, 59, 119], [116, 90, 156, 198, 373, 326]], [128, 256, 512]]Model Summary: 270 layers, 7022326 parameters, 7022326 gradients, 15.9 GFLOPs五、YOLOv5n改进工作
完成二后,在YOLOv5项目文件下的models文件夹下创建新的文件yolov5n-simsppf.yaml,导入如下代码。
# Parameters
nc: 1  # number of classes
depth_multiple: 0.33  # model depth multiple
width_multiple: 0.25  # 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, SimSPPF, [1024]],]# YOLOv5 v6.0 head
head:[[-1, 1, Conv, [512, 1, 1]],[-1, 1, nn.Upsample, [None, 2, 'nearest']],[[-1, 6], 1, Concat, [1]],  # 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, Concat, [1]],  # cat backbone P3[-1, 3, C3, [256, False]],  # 17 (P3/8-small)[-1, 1, Conv, [256, 3, 2]],[[-1, 14], 1, Concat, [1]],  # cat head P4[-1, 3, C3, [512, False]],  # 20 (P4/16-medium)[-1, 1, Conv, [512, 3, 2]],[[-1, 10], 1, Concat, [1]],  # cat head P5[-1, 3, C3, [1024, False]],  # 23 (P5/32-large)[[17, 20, 23], 1, Detect, [nc, anchors]],  # Detect(P3, P4, P5)]
from  n    params  module                                  arguments                     0                -1  1      1760  models.common.Conv                      [3, 16, 6, 2, 2]              1                -1  1      4672  models.common.Conv                      [16, 32, 3, 2]                2                -1  1      4800  models.common.C3                        [32, 32, 1]                   3                -1  1     18560  models.common.Conv                      [32, 64, 3, 2]                4                -1  2     29184  models.common.C3                        [64, 64, 2]                   5                -1  1     73984  models.common.Conv                      [64, 128, 3, 2]               6                -1  3    156928  models.common.C3                        [128, 128, 3]                 7                -1  1    295424  models.common.Conv                      [128, 256, 3, 2]              8                -1  1    296448  models.common.C3                        [256, 256, 1]                 9                -1  1    164608  models.morepooling.SimSPPF              [256, 256, 5]                 10                -1  1     33024  models.common.Conv                      [256, 128, 1, 1]              11                -1  1         0  torch.nn.modules.upsampling.Upsample    [None, 2, 'nearest']          12           [-1, 6]  1         0  models.common.Concat                    [1]                           13                -1  1     90880  models.common.C3                        [256, 128, 1, False]          14                -1  1      8320  models.common.Conv                      [128, 64, 1, 1]               15                -1  1         0  torch.nn.modules.upsampling.Upsample    [None, 2, 'nearest']          16           [-1, 4]  1         0  models.common.Concat                    [1]                           17                -1  1     22912  models.common.C3                        [128, 64, 1, False]           18                -1  1     36992  models.common.Conv                      [64, 64, 3, 2]                19          [-1, 14]  1         0  models.common.Concat                    [1]                           20                -1  1     74496  models.common.C3                        [128, 128, 1, False]          21                -1  1    147712  models.common.Conv                      [128, 128, 3, 2]              22          [-1, 10]  1         0  models.common.Concat                    [1]                           23                -1  1    296448  models.common.C3                        [256, 256, 1, False]          24      [17, 20, 23]  1      8118  models.yolo.Detect                      [1, [[10, 13, 16, 30, 33, 23], [30, 61, 62, 45, 59, 119], [116, 90, 156, 198, 373, 326]], [64, 128, 256]]Model Summary: 270 layers, 1765270 parameters, 1765270 gradients, 4.2 GFLOPs
六、代码解释
simsppf又称为“简单的”sppf.
定义了两个深度学习模块:SimConv 和 SimSPPF。它们是YOLOv6检测模型中的一部分,旨在简化网络结构和提高效率。
SimConv
这是一个简化版的卷积块,它包含一个卷积层、批量归一化(Batch Normalization)和ReLU激活函数。相比于标准的卷积块,这里没有使用更复杂的激活函数如SiLU或Leaky ReLU,而是选择了计算成本较低的ReLU。
优点:
- 简单性: 使用ReLU减少了计算复杂度,加速训练过程。
- 可融合性: 提供了forward_fuse方法,允许在网络优化过程中融合BN和卷积操作,进一步加速推理速度。
缺点:
- 表达能力: 相比于更复杂的激活函数,ReLU可能在某些任务上限制了网络的表达能力。
- 梯度消失问题: 虽然ReLU解决了传统sigmoid和tanh函数的梯度消失问题,但在输入为负数时其梯度为零,这仍然可能导致部分神经元“死亡”。
SimSPPF
这是对空间金字塔池化(Spatial Pyramid Pooling, SPP)模块的简化版本,通常用于增强特征的尺度不变性。这个模块使用多个最大池化层来捕获不同尺度的信息,并通过1x1卷积进行通道数调整。
优点:
- 尺度不变性: 多尺度的最大池化有助于模型捕捉到不同大小的目标信息。
- 参数效率: 使用了较少的参数量,同时保持了SPP模块的大部分功能。
- 灵活性: 可以通过改变kernel_size参数来适应不同的输入尺寸或特征图需求。
缺点:
- 计算资源: 尽管进行了简化,SPPF仍然涉及多次最大池化操作,这可能会增加计算负担,尤其是在高分辨率图像上。
- 信息损失: 最大池化操作可能会导致一些空间细节的丢失,这可能会影响最终的检测精度。
运行后若打印出如上文本代表改进成功。
运行后打印如上代码说明改进成功。
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