改进YOLOv5系列：27.YOLOv5 结合 Swin Transformer V2结构，Swin Transformer V2：通向视觉大模型之路

最新创新点改进推荐

-统一使用 YOLO 代码框架，结合不同模块来构建不同的YOLO目标检测模型。

《芒果书》系列改进专栏内的改进文章，均包含多种模型改进方式，均适用于YOLOv3 、YOLOv4 、 YOLOR 、 YOLOX 、YOLOv5 、 YOLOv7 、 YOLOv8 改进（重点）！！！

专栏创新点教程 均有不少同学反应和我说已经在自己的数据集上有效涨点啦！！ 包括COCO数据集也能涨点

所有文章博客均包含 改进源代码部分，一键训练即可

对应专栏订阅的越早，就可以越早使用原创创新点去改进模型，抢先一步

点击查看详情：YOLOv5改进、YOLOv7改进｜YOLO改进超过50种注意力机制，全篇共计30万字（内附改进源代码），原创改进50种Attention注意力机制和Transformer自注意力机制

芒果书 点击以下链接 查看文章目录详情

• ☁️：一、CSDN原创《芒果改进YOLO高阶指南》强烈改进涨点推荐！推荐指数：

• ☁️：二、CSDN原创YOLO进阶 | 《芒果改进YOLO进阶指南》改进涨点推荐！推荐指数：

• ☁️：三、CSDN独家全网首发专栏 | 《目标检测YOLO改进指南》改进涨点推荐！推荐指数：

YOLO系列 + Swin Transformer V2 结合应用 为 CSDN芒果汁没有芒果 首发更新博文

点Star 和 Fork，第一时间获取同步更新！

链接：https://github.com/iscyy/yoloair

对于这块有疑问的，可以在评论区提出，或者私信CSDN。

本篇是《YOLOv5结合Swin Transformer V2结构》的修改 演示

使用YOLOv5网络作为示范，可以加入到 YOLOv7、YOLOX、YOLOR、YOLOv4、Scaled_YOLOv4、YOLOv3等一系列YOLO算法模块

文章目录

• • 最新创新点改进推荐
  • 点击查看详情：[YOLOv5改进、YOLOv7改进｜YOLO改进超过50种注意力机制，全篇共计30万字（内附改进源代码），原创改进50种Attention注意力机制和Transformer自注意力机制](https://blog.csdn.net/qq_38668236/article/details/129137111)
  • YOLO系列 + Swin Transformer V2 结合应用 为 `CSDN芒果汁没有芒果` 首发更新博文
  • Swin Transformer论文
  • YOLOv5结合Swin Transformer-V2 演示教程
  • • YOLOv5的yaml配置文件
    • common.py配置
    • yolo.py配置
    • 训练yolov5_swin_transfomrer-V2模型

Swin Transformer论文

该论文作者提出了缩放 Swin Transformer 的技术 多达 30 亿个参数，使其能够使用多达 1,536 个图像进行训练1,536 分辨率。通过扩大容量和分辨率，Swin Transformer 在四个具有代表性的视觉基准上创造了新记录：ImageNet-V2 图像分类的84.0% top-1 准确率，COCO 对象检测的63.1 / 54.4 box / mask mAP，ADE20K 语义分割的59.9 mIoU，和86.8%Kinetics-400 视频动作分类的前 1 准确率。我们的技术通常适用于扩大视觉模型，但尚未像 NLP 语言模型那样被广泛探索，部分原因是在训练和应用方面存在以下困难：1）视觉模型经常面临大规模的不稳定性问题和 2）许多下游视觉任务需要高分辨率图像或窗口，目前尚不清楚如何有效地将低分辨率预训练的模型转移到更高分辨率的模型。当图像分辨率很高时，GPU 内存消耗也是一个问题。为了解决这些问题，我们提出了几种技术，并通过使用 Swin Transformer 作为案例研究来说明：1）后归一化技术和缩放余弦注意方法，以提高大型视觉模型的稳定性；2) 一种对数间隔的连续位置偏差技术，可有效地将在低分辨率图像和窗口上预训练的模型转移到其更高分辨率的对应物上。此外，我们分享了我们的关键实现细节，这些细节可以显着节省 GPU 内存消耗，从而使使用常规 GPU 训练大型视觉模型变得可行。使用这些技术和自我监督的预训练，我们成功训练了一个强大的 30 亿个 Swin Transformer 模型，并有效地将其转移到涉及高分辨率图像或窗口的各种视觉任务中，在各种的基准。代码将在 我们分享了我们的关键实现细节，这些细节可以显着节省 GPU 内存消耗，从而使使用常规 GPU 训练大型视觉模型变得可行。使用这些技术和自我监督的预训练，我们成功训练了一个强大的 30 亿个 Swin Transformer 模型，并有效地将其转移到涉及高分辨率图像或窗口的各种视觉任务中，在各种的基准。代码将在 我们分享了我们的关键实现细节，这些细节可以显着节省 GPU 内存消耗，从而使使用常规 GPU 训练大型视觉模型变得可行。使用这些技术和自我监督的预训练，我们成功训练了一个强大的 30 亿个 Swin Transformer 模型，并有效地将其转移到涉及高分辨率图像或窗口的各种视觉任务中，在各种的基准。代码将在 我们成功训练了一个强大的 30 亿个 Swin Transformer 模型，并将其有效地转移到涉及高分辨率图像或窗口的各种视觉任务中，在各种基准测试中达到了最先进的精度。代码将在 我们成功训练了一个强大的 30 亿个 Swin Transformer 模型，并将其有效地转移到涉及高分辨率图像或窗口的各种视觉任务中，在各种基准测试中达到了最先进的精度。

YOLOv5结合Swin Transformer-V2 演示教程

YOLOv5的yaml配置文件

首先增加以下yolov5_swin_transfomrer.yaml文件

# YOLOv5by Ultralytics, GPL-3.0 license# Parametersnc: 80# number of classesdepth_multiple: 0.33# model depth multiplewidth_multiple: 0.50# layer channel multipleanchors:- [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 by yoloairbackbone:# [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, SwinV2_CSPB, [256, 256]], [-1, 1, Conv, [1024, 3, 2]],# 7-P5/32 [-1, 3, SwinV2_CSPB, [512, 512]],# 9 <--- ST2CSPB() Transformer module [-1, 1, SPPF, [1024, 5]],# 9]# YOLOv5 v6.0 headhead:[[-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)]

common.py配置

在./models/common.py文件中增加以下模块，直接复制即可

class WindowAttention_v2(nn.Module):def __init__(self, dim, window_size, num_heads, qkv_bias=True, attn_drop=0., proj_drop=0., pretrained_window_size=[0, 0]):super().__init__()self.dim = dimself.window_size = window_size# Wh, Wwself.pretrained_window_size = pretrained_window_sizeself.num_heads = num_headsself.logit_scale = nn.Parameter(torch.log(10 * torch.ones((num_heads, 1, 1))), requires_grad=True)# mlp to generate continuous relative position biasself.cpb_mlp = nn.Sequential(nn.Linear(2, 512, bias=True), nn.ReLU(inplace=True), nn.Linear(512, num_heads, bias=False))# get relative_coords_tablerelative_coords_h = torch.arange(-(self.window_size[0] - 1), self.window_size[0], dtype=torch.float32)relative_coords_w = torch.arange(-(self.window_size[1] - 1), self.window_size[1], dtype=torch.float32)relative_coords_table = torch.stack(torch.meshgrid([relative_coords_h,relative_coords_w])).permute(1, 2, 0).contiguous().unsqueeze(0)# 1, 2*Wh-1, 2*Ww-1, 2if pretrained_window_size[0] > 0:relative_coords_table[:, :, :, 0] /= (pretrained_window_size[0] - 1)relative_coords_table[:, :, :, 1] /= (pretrained_window_size[1] - 1)else:relative_coords_table[:, :, :, 0] /= (self.window_size[0] - 1)relative_coords_table[:, :, :, 1] /= (self.window_size[1] - 1)relative_coords_table *= 8# normalize to -8, 8relative_coords_table = torch.sign(relative_coords_table) * torch.log2(torch.abs(relative_coords_table) + 1.0) / np.log2(8)self.register_buffer("relative_coords_table", relative_coords_table)# get pair-wise relative position index for each token inside the windowcoords_h = torch.arange(self.window_size[0])coords_w = torch.arange(self.window_size[1])coords = torch.stack(torch.meshgrid([coords_h, coords_w]))# 2, Wh, Wwcoords_flatten = torch.flatten(coords, 1)# 2, Wh*Wwrelative_coords = coords_flatten[:, :, None] - coords_flatten[:, None, :]# 2, Wh*Ww, Wh*Wwrelative_coords = relative_coords.permute(1, 2, 0).contiguous()# Wh*Ww, Wh*Ww, 2relative_coords[:, :, 0] += self.window_size[0] - 1# shift to start from 0relative_coords[:, :, 1] += self.window_size[1] - 1relative_coords[:, :, 0] *= 2 * self.window_size[1] - 1relative_position_index = relative_coords.sum(-1)# Wh*Ww, Wh*Wwself.register_buffer("relative_position_index", relative_position_index)self.qkv = nn.Linear(dim, dim * 3, bias=False)if qkv_bias:self.q_bias = nn.Parameter(torch.zeros(dim))self.v_bias = nn.Parameter(torch.zeros(dim))else:self.q_bias = Noneself.v_bias = Noneself.attn_drop = nn.Dropout(attn_drop)self.proj = nn.Linear(dim, dim)self.proj_drop = nn.Dropout(proj_drop)self.softmax = nn.Softmax(dim=-1)def forward(self, x, mask=None):B_, N, C = x.shapeqkv_bias = Noneif self.q_bias is not None:qkv_bias = torch.cat((self.q_bias, torch.zeros_like(self.v_bias, requires_grad=False), self.v_bias))qkv = F.linear(input=x, weight=self.qkv.weight, bias=qkv_bias)qkv = qkv.reshape(B_, N, 3, self.num_heads, -1).permute(2, 0, 3, 1, 4)q, k, v = qkv[0], qkv[1], qkv[2]# make torchscript happy (cannot use tensor as tuple)# cosine attentionattn = (F.normalize(q, dim=-1) @ F.normalize(k, dim=-1).transpose(-2, -1))logit_scale = torch.clamp(self.logit_scale, max=torch.log(torch.tensor(1. / 0.01))).exp()attn = attn * logit_scalerelative_position_bias_table = self.cpb_mlp(self.relative_coords_table).view(-1, self.num_heads)relative_position_bias = relative_position_bias_table[self.relative_position_index.view(-1)].view(self.window_size[0] * self.window_size[1], self.window_size[0] * self.window_size[1], -1)# Wh*Ww,Wh*Ww,nHrelative_position_bias = relative_position_bias.permute(2, 0, 1).contiguous()# nH, Wh*Ww, Wh*Wwrelative_position_bias = 16 * torch.sigmoid(relative_position_bias)attn = attn + relative_position_bias.unsqueeze(0)if mask is not None:nW = mask.shape[0]attn = attn.view(B_ // nW, nW, self.num_heads, N, N) + mask.unsqueeze(1).unsqueeze(0)attn = attn.view(-1, self.num_heads, N, N)attn = self.softmax(attn)else:attn = self.softmax(attn)attn = self.attn_drop(attn)try:x = (attn @ v).transpose(1, 2).reshape(B_, N, C)except:x = (attn.half() @ v).transpose(1, 2).reshape(B_, N, C)x = self.proj(x)x = self.proj_drop(x)return xdef extra_repr(self) -> str:return f'dim={self.dim}, window_size={self.window_size}, ' \ f'pretrained_window_size={self.pretrained_window_size}, num_heads={self.num_heads}'def flops(self, N):# calculate flops for 1 window with token length of Nflops = 0# qkv = self.qkv(x)flops += N * self.dim * 3 * self.dim# attn = (q @ k.transpose(-2, -1))flops += self.num_heads * N * (self.dim // self.num_heads) * N#x = (attn @ v)flops += self.num_heads * N * N * (self.dim // self.num_heads)# x = self.proj(x)flops += N * self.dim * self.dimreturn flopsclass Mlp_v2(nn.Module):def __init__(self, in_features, hidden_features=None, out_features=None, act_layer=nn.SiLU, drop=0.):super().__init__()out_features = out_features or in_featureshidden_features = hidden_features or in_featuresself.fc1 = nn.Linear(in_features, hidden_features)self.act = act_layer()self.fc2 = nn.Linear(hidden_features, out_features)self.drop = nn.Dropout(drop)def forward(self, x):x = self.fc1(x)x = self.act(x)x = self.drop(x)x = self.fc2(x)x = self.drop(x)return x# add 2 functionsclass SwinTransformerLayer_v2(nn.Module):def __init__(self, dim, num_heads, window_size=7, shift_size=0, mlp_ratio=4., qkv_bias=True, drop=0., attn_drop=0., drop_path=0., act_layer=nn.SiLU, norm_layer=nn.LayerNorm, pretrained_window_size=0):super().__init__()self.dim = dim#self.input_resolution = input_resolutionself.num_heads = num_headsself.window_size = window_sizeself.shift_size = shift_sizeself.mlp_ratio = mlp_ratio#if min(self.input_resolution) <= self.window_size:## if window size is larger than input resolution, we don't partition windows#self.shift_size = 0#self.window_size = min(self.input_resolution)assert 0 <= self.shift_size < self.window_size, "shift_size must in 0-window_size"self.norm1 = norm_layer(dim)self.attn = WindowAttention_v2(dim, window_size=(self.window_size, self.window_size), num_heads=num_heads,qkv_bias=qkv_bias, attn_drop=attn_drop, proj_drop=drop,pretrained_window_size=(pretrained_window_size, pretrained_window_size))self.drop_path = DropPath(drop_path) if drop_path > 0. else nn.Identity()self.norm2 = norm_layer(dim)mlp_hidden_dim = int(dim * mlp_ratio)self.mlp = Mlp_v2(in_features=dim, hidden_features=mlp_hidden_dim, act_layer=act_layer, drop=drop)def create_mask(self, H, W):# calculate attention mask for SW-MSAimg_mask = torch.zeros((1, H, W, 1))# 1 H W 1h_slices = (slice(0, -self.window_size),slice(-self.window_size, -self.shift_size),slice(-self.shift_size, None))w_slices = (slice(0, -self.window_size),slice(-self.window_size, -self.shift_size),slice(-self.shift_size, None))cnt = 0for h in h_slices:for w in w_slices:img_mask[:, h, w, :] = cntcnt += 1mask_windows = window_partition(img_mask, self.window_size)# nW, window_size, window_size, 1mask_windows = mask_windows.view(-1, self.window_size * self.window_size)attn_mask = mask_windows.unsqueeze(1) - mask_windows.unsqueeze(2)attn_mask = attn_mask.masked_fill(attn_mask != 0, float(-100.0)).masked_fill(attn_mask == 0, float(0.0))return attn_maskdef forward(self, x):# reshape x[b c h w] to x[b l c]_, _, H_, W_ = x.shapePadding = Falseif min(H_, W_) < self.window_size or H_ % self.window_size!=0 or W_ % self.window_size!=0:Padding = True# print(f'img_size {min(H_, W_)} is less than (or not divided by) window_size {self.window_size}, Padding.')pad_r = (self.window_size - W_ % self.window_size) % self.window_sizepad_b = (self.window_size - H_ % self.window_size) % self.window_sizex = F.pad(x, (0, pad_r, 0, pad_b))# print('2', x.shape)B, C, H, W = x.shapeL = H * Wx = x.permute(0, 2, 3, 1).contiguous().view(B, L, C)# b, L, c# create mask from init to forwardif self.shift_size > 0:attn_mask = self.create_mask(H, W).to(x.device)else:attn_mask = Noneshortcut = xx = x.view(B, H, W, C)# cyclic shiftif self.shift_size > 0:shifted_x = torch.roll(x, shifts=(-self.shift_size, -self.shift_size), dims=(1, 2))else:shifted_x = x# partition windowsx_windows = window_partition_v2(shifted_x, self.window_size)# nW*B, window_size, window_size, Cx_windows = x_windows.view(-1, self.window_size * self.window_size, C)# nW*B, window_size*window_size, C# W-MSA/SW-MSAattn_windows = self.attn(x_windows, mask=attn_mask)# nW*B, window_size*window_size, C# merge windowsattn_windows = attn_windows.view(-1, self.window_size, self.window_size, C)shifted_x = window_reverse_v2(attn_windows, self.window_size, H, W)# B H' W' C# reverse cyclic shiftif self.shift_size > 0:x = torch.roll(shifted_x, shifts=(self.shift_size, self.shift_size), dims=(1, 2))else:x = shifted_xx = x.view(B, H * W, C)x = shortcut + self.drop_path(self.norm1(x))# FFNx = x + self.drop_path(self.norm2(self.mlp(x)))x = x.permute(0, 2, 1).contiguous().view(-1, C, H, W)# b c h wif Padding:x = x[:, :, :H_, :W_]# reverse paddingreturn xdef extra_repr(self) -> str:return f"dim={self.dim}, input_resolution={self.input_resolution}, num_heads={self.num_heads}, " \ f"window_size={self.window_size}, shift_size={self.shift_size}, mlp_ratio={self.mlp_ratio}"def flops(self):flops = 0H, W = self.input_resolution# norm1flops += self.dim * H * W# W-MSA/SW-MSAnW = H * W / self.window_size / self.window_sizeflops += nW * self.attn.flops(self.window_size * self.window_size)# mlpflops += 2 * H * W * self.dim * self.dim * self.mlp_ratio# norm2flops += self.dim * H * Wreturn flopsclass SwinTransformer2Block(nn.Module):def __init__(self, c1, c2, num_heads, num_layers, window_size=7):super().__init__()self.conv = Noneif c1 != c2:self.conv = Conv(c1, c2)# remove input_resolutionself.blocks = nn.Sequential(*[SwinTransformerLayer_v2(dim=c2, num_heads=num_heads, window_size=window_size, shift_size=0 if (i % 2 == 0) else window_size // 2) for i in range(num_layers)])def forward(self, x):if self.conv is not None:x = self.conv(x)x = self.blocks(x)return xclass SwinV2_CSPB(nn.Module):# CSP Bottleneck https://github.com/WongKinYiu/CrossStagePartialNetworksdef __init__(self, c1, c2, n=1, shortcut=False, g=1, e=0.5):# ch_in, ch_out, number, shortcut, groups, expansionsuper(SwinV2_CSPB, self).__init__()c_ = int(c2)# hidden channelsself.cv1 = Conv(c1, c_, 1, 1)self.cv2 = Conv(c_, c_, 1, 1)self.cv3 = Conv(2 * c_, c2, 1, 1)num_heads = c_ // 32self.m = SwinTransformer2Block(c_, c_, num_heads, n)#self.m = nn.Sequential(*[Bottleneck(c_, c_, shortcut, g, e=1.0) for _ in range(n)])def forward(self, x):x1 = self.cv1(x)y1 = self.m(x1)y2 = self.cv2(x1)return self.cv3(torch.cat((y1, y2), dim=1))

yolo.py配置

不需要

训练yolov5_swin_transfomrer-V2模型

python train.py --cfg yolov5_swin_transfomrer-V2.yaml