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RT-DETR改进策略【Conv和Transformer】CVPR-2024Single-HeadSelf-Attention单头自注意力-

RT-DETR改进策略【Conv和Transformer】| CVPR-2024 Single-Head Self-Attention 单头自注意力

一、本文介绍

本文记录的是 利用 单头自注意力SHSA 改进 RT-DETR 检测模型 ,详细说明了优化原因,注意事项等。传统的自注意力机制虽能提升性能,但计算量大,内存访问成本高,而 SHSA 从根本上避免了多注意力头机制带来的计算冗余。并且改进后的模型在相同计算预算下,能够堆叠更多宽度更大的块,从而提高性能。



二、Single-Head Self-Attention介绍

2.1 出发点

  • 宏观设计层面 :传统的高效模型大多采用 4 × 4 4×4 4 × 4 的patchify stem和4阶段配置,存在空间冗余,导致早期阶段速度瓶颈且 内存访问成本高 。研究发现采用更大步长的 16 × 16 16×16 16 × 16 patchify stem和3阶段设计可减少空间冗余,降低内存访问成本,提高性能。
  • 微观设计层面 :**多注意力头机制(MHSA)**在计算和应用注意力映射时虽能提升性能,但存在冗余。尤其在早期阶段部分头类似卷积操作,后期阶段头之间存在大量冗余,且多数现有方法处理头冗余需先训练完整网络再修剪,计算资源和内存消耗大。

2.2 原理

  • 基于上述宏观和微观设计的分析结果,提出 Single - Head Self - Attention(SHSA) 模块。它仅在部分输入通道( C p = r C C_{p}=rC C p = r C )上应用单头注意力层进行空间特征聚合,其余通道保持不变,默认 r = 1 / 4.6 r = 1/4.6 r = 1/4.6

2.3 结构

2.3.1 输入通道处理

将输入 X X X 按通道分为两部分 X a t t X_{att} X a tt X r e s X_{res} X res ,其中 X a t t X_{att} X a tt 包含 C p C_{p} C p 个通道, X r e s X_{res} X res 包含 C − C p C - C_{p} C C p 个通道。

2.3.2 注意力计算

X a t t X_{att} X a tt 应用注意力机制,计算 X ~ a t t = A t t e n t i o n ( X a t t W Q , X a t t W K , X a t t W V ) \tilde{X}_{att}=Attention(X_{att}W^{Q},X_{att}W^{K},X_{att}W^{V}) X ~ a tt = A tt e n t i o n ( X a tt W Q , X a tt W K , X a tt W V ) ,其中 A t t e n t i o n ( Q , K , V ) = S o f t m a x ( Q K ⊤ / d q k ) V Attention(Q,K,V)=Softmax(QK^{\top}/\sqrt{d_{qk}})V A tt e n t i o n ( Q , K , V ) = S o f t ma x ( Q K / d q k ) V d q k d_{qk} d q k 默认值为16。

2.3.3 输出拼接与投影

X ~ a t t \tilde{X}_{att} X ~ a tt X r e s X_{res} X res 拼接得到 S H S A ( X ) = C o n c a t ( X ~ a t t , X r e s ) W O SHSA(X)=Concat(\tilde{X}_{att},X_{res})W^{O} S H S A ( X ) = C o n c a t ( X ~ a tt , X res ) W O ,最终投影应用于所有通道,确保注意力特征有效传播到剩余通道。

在这里插入图片描述

  1. 优势
    • 减少冗余 :从根本上避免了多注意力头机制带来的计算冗余。
    • 降低内存访问成本 :仅处理部分通道,减少了内存访问成本。
    • 提高性能 :在相同计算预算下,能够堆叠更多宽度更大的块,从而提高性能。
    • 简化训练和推理过程 :相比现有处理头冗余的方法,无需先训练完整网络再修剪,训练和推理过程更加高效。

论文: https://arxiv.org/pdf/2401.16456
源码: https://github.com/ysj9909/SHViT

三、SHSA的实现代码

SHSA模块 的实现代码如下:

import torch
import torch.nn as nn
import torch.nn.functional as F

from ultralytics.nn.modules.conv import LightConv

class GroupNorm(torch.nn.GroupNorm):
    """
    Group Normalization with 1 group.
    Input: tensor in shape [B, C, H, W]
    """
    def __init__(self, num_channels, **kwargs):
        super().__init__(1, num_channels, **kwargs)

class Conv2d_BN(torch.nn.Sequential):
    def __init__(self, a, b, ks=1, stride=1, pad=0, dilation=1,
                 groups=1, bn_weight_init=1):
        super().__init__()
        self.add_module('c', torch.nn.Conv2d(
            a, b, ks, stride, pad, dilation, groups, bias=False))
        self.add_module('bn', torch.nn.BatchNorm2d(b))
        torch.nn.init.constant_(self.bn.weight, bn_weight_init)
        torch.nn.init.constant_(self.bn.bias, 0)

    @torch.no_grad()
    def fuse(self):
        c, bn = self._modules.values()
        w = bn.weight / (bn.running_var + bn.eps)**0.5
        w = c.weight * w[:, None, None, None]
        b = bn.bias - bn.running_mean * bn.weight / \
            (bn.running_var + bn.eps)**0.5
        m = torch.nn.Conv2d(w.size(1) * self.c.groups, w.size(
            0), w.shape[2:], stride=self.c.stride, padding=self.c.padding, dilation=self.c.dilation, groups=self.c.groups,
            device=c.weight.device)
        m.weight.data.copy_(w)
        m.bias.data.copy_(b)
        return m

class SHSA(torch.nn.Module):
    """Single-Head Self-Attention"""

    def __init__(self, dim, qk_dim=16, pdim=32):
        super().__init__()
        self.scale = qk_dim ** -0.5
        self.qk_dim = qk_dim
        self.dim = dim
        self.pdim = pdim

        self.pre_norm = GroupNorm(pdim)

        self.qkv = Conv2d_BN(pdim, qk_dim * 2 + pdim)
        self.proj = torch.nn.Sequential(torch.nn.ReLU(), Conv2d_BN(
            dim, dim, bn_weight_init=0))

    def forward(self, x):
        B, C, H, W = x.shape
        x1, x2 = torch.split(x, [self.pdim, self.dim - self.pdim], dim=1)
        x1 = self.pre_norm(x1)
        qkv = self.qkv(x1)
        q, k, v = qkv.split([self.qk_dim, self.qk_dim, self.pdim], dim=1)
        q, k, v = q.flatten(2), k.flatten(2), v.flatten(2)

        attn = (q.transpose(-2, -1) @ k) * self.scale
        attn = attn.softmax(dim=-1)
        x1 = (v @ attn.transpose(-2, -1)).reshape(B, self.pdim, H, W)
        x = self.proj(torch.cat([x1, x2], dim=1))

        return x

def autopad(k, p=None, d=1):  # kernel, padding, dilation
    """Pad to 'same' shape outputs."""
    if d > 1:
        k = d * (k - 1) + 1 if isinstance(k, int) else [d * (x - 1) + 1 for x in k]  # actual kernel-size
    if p is None:
        p = k // 2 if isinstance(k, int) else [x // 2 for x in k]  # auto-pad
    return p

class Conv(nn.Module):
    """Standard convolution with args(ch_in, ch_out, kernel, stride, padding, groups, dilation, activation)."""
 
    default_act = nn.SiLU()  # default activation
 
    def __init__(self, c1, c2, k=1, s=1, p=None, g=1, d=1, act=True):
        """Initialize Conv layer with given arguments including activation."""
        super().__init__()
        self.conv = nn.Conv2d(c1, c2, k, s, autopad(k, p, d), groups=g, dilation=d, bias=False)
        self.bn = nn.BatchNorm2d(c2)
        self.act = self.default_act if act is True else act if isinstance(act, nn.Module) else nn.Identity()
 
    def forward(self, x):
        """Apply convolution, batch normalization and activation to input tensor."""
        return self.act(self.bn(self.conv(x)))
 
    def forward_fuse(self, x):
        """Perform transposed convolution of 2D data."""
        return self.act(self.conv(x))

class HGBlock_SHSA(nn.Module):
    """
    HG_Block of PPHGNetV2 with 2 convolutions and LightConv.

    https://github.com/PaddlePaddle/PaddleDetection/blob/develop/ppdet/modeling/backbones/hgnet_v2.py
    """

    def __init__(self, c1, cm, c2, k=3, n=6, lightconv=False, shortcut=False, act=nn.ReLU()):
        """Initializes a CSP Bottleneck with 1 convolution using specified input and output channels."""
        super().__init__()
        block = LightConv if lightconv else Conv
        self.m = nn.ModuleList(block(c1 if i == 0 else cm, cm, k=k, act=act) for i in range(n))
        self.sc = Conv(c1 + n * cm, c2 // 2, 1, 1, act=act)  # squeeze conv
        self.ec = Conv(c2 // 2, c2, 1, 1, act=act)  # excitation conv
        self.add = shortcut and c1 == c2
        self.cv = SHSA(c2)
        
    def forward(self, x):
        """Forward pass of a PPHGNetV2 backbone layer."""
        y = [x]
        y.extend(m(y[-1]) for m in self.m)
        y = self.cv(self.ec(self.sc(torch.cat(y, 1))))
        return y + x if self.add else y


四、添加步骤

4.1 改进点1

模块改进方法 1️⃣:直接加入 SHSA模块
SHSA模块 添加后如下:

在这里插入图片描述

注意❗:在 5.2和5.3小节 中需要声明的模块名称为: SHSA

4.2 改进点2⭐

模块改进方法 2️⃣:基于 SHSA模块 HGBlock

第二种改进方法是对 RT-DETR 中的 HGBlock模块 进行改进。

改进代码如下:

添加 SHSA 改进 HGBlock 模块,并重命名为 HGBlock_SHSA

class HGBlock_SHSA(nn.Module):
    """
    HG_Block of PPHGNetV2 with 2 convolutions and LightConv.

    https://github.com/PaddlePaddle/PaddleDetection/blob/develop/ppdet/modeling/backbones/hgnet_v2.py
    """

    def __init__(self, c1, cm, c2, k=3, n=6, lightconv=False, shortcut=False, act=nn.ReLU()):
        """Initializes a CSP Bottleneck with 1 convolution using specified input and output channels."""
        super().__init__()
        block = LightConv if lightconv else Conv
        self.m = nn.ModuleList(block(c1 if i == 0 else cm, cm, k=k, act=act) for i in range(n))
        self.sc = Conv(c1 + n * cm, c2 // 2, 1, 1, act=act)  # squeeze conv
        self.ec = Conv(c2 // 2, c2, 1, 1, act=act)  # excitation conv
        self.add = shortcut and c1 == c2
        self.cv = SHSA(c2)
        
    def forward(self, x):
        """Forward pass of a PPHGNetV2 backbone layer."""
        y = [x]
        y.extend(m(y[-1]) for m in self.m)
        y = self.cv(self.ec(self.sc(torch.cat(y, 1))))
        return y + x if self.add else y

在这里插入图片描述

注意❗:在 5.2和5.3小节 中需要声明的模块名称为: HGBlock_SHSA


五、添加步骤

5.1 修改一

① 在 ultralytics/nn/ 目录下新建 AddModules 文件夹用于存放模块代码

② 在 AddModules 文件夹下新建 SHSA.py ,将 第三节 中的代码粘贴到此处

在这里插入图片描述

5.2 修改二

AddModules 文件夹下新建 __init__.py (已有则不用新建),在文件内导入模块: from .SHSA import *

在这里插入图片描述

5.3 修改三

ultralytics/nn/modules/tasks.py 文件中,需要在两处位置添加各模块类名称。

首先:导入模块

在这里插入图片描述

其次:在 parse_model函数 中注册 SHSA HGBlock_SHSA 模块

在这里插入图片描述
在这里插入图片描述
在这里插入图片描述


六、yaml模型文件

6.1 模型改进版本一

在代码配置完成后,配置模型的YAML文件。

此处以 ultralytics/cfg/models/rt-detr/rtdetr-l.yaml 为例,在同目录下创建一个用于自己数据集训练的模型文件 rtdetr-l-SHSA.yaml

rtdetr-l.yaml 中的内容复制到 rtdetr-l-SHSA.yaml 文件下,修改 nc 数量等于自己数据中目标的数量。
在骨干网络中添加 SHSA模块 只需要填入一个参数,和前一层通道数一致

# Ultralytics YOLO 🚀, AGPL-3.0 license
# RT-DETR-l object detection model with P3-P5 outputs. For details see https://docs.ultralytics.com/models/rtdetr

# Parameters
nc: 1 # number of classes
scales: # model compound scaling constants, i.e. 'model=yolov8n-cls.yaml' will call yolov8-cls.yaml with scale 'n'
  # [depth, width, max_channels]
  l: [1.00, 1.00, 1024]

backbone:
  # [from, repeats, module, args]
  - [-1, 1, HGStem, [32, 48]] # 0-P2/4
  - [-1, 6, HGBlock, [48, 128, 3]] # stage 1

  - [-1, 1, DWConv, [128, 3, 2, 1, False]] # 2-P3/8
  - [-1, 6, HGBlock, [96, 512, 3]] # stage 2

  - [-1, 1, DWConv, [512, 3, 2, 1, False]] # 4-P4/16
  - [-1, 6, HGBlock, [192, 1024, 5, True, False]] # cm, c2, k, light, shortcut
  - [-1, 6, HGBlock, [192, 1024, 5, True, True]]
  - [-1, 6, HGBlock, [192, 1024, 5, True, True]] # stage 3

  - [-1, 1, DWConv, [1024, 3, 2, 1, False]] # 8-P5/32
  - [-1, 6, SHSA, [1024]] # stage 4

head:
  - [-1, 1, Conv, [256, 1, 1, None, 1, 1, False]] # 10 input_proj.2
  - [-1, 1, AIFI, [1024, 8]]
  - [-1, 1, Conv, [256, 1, 1]] # 12, Y5, lateral_convs.0

  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [7, 1, Conv, [256, 1, 1, None, 1, 1, False]] # 14 input_proj.1
  - [[-2, -1], 1, Concat, [1]]
  - [-1, 3, RepC3, [256]] # 16, fpn_blocks.0
  - [-1, 1, Conv, [256, 1, 1]] # 17, Y4, lateral_convs.1

  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [3, 1, Conv, [256, 1, 1, None, 1, 1, False]] # 19 input_proj.0
  - [[-2, -1], 1, Concat, [1]] # cat backbone P4
  - [-1, 3, RepC3, [256]] # X3 (21), fpn_blocks.1

  - [-1, 1, Conv, [256, 3, 2]] # 22, downsample_convs.0
  - [[-1, 17], 1, Concat, [1]] # cat Y4
  - [-1, 3, RepC3, [256]] # F4 (24), pan_blocks.0

  - [-1, 1, Conv, [256, 3, 2]] # 25, downsample_convs.1
  - [[-1, 12], 1, Concat, [1]] # cat Y5
  - [-1, 3, RepC3, [256]] # F5 (27), pan_blocks.1

  - [[21, 24, 27], 1, RTDETRDecoder, [nc]] # Detect(P3, P4, P5)

6.2 模型改进版本二⭐

此处同样以 ultralytics/cfg/models/rt-detr/rtdetr-l.yaml 为例,在同目录下创建一个用于自己数据集训练的模型文件 rtdetr-l-HGBlock_SHSA.yaml

rtdetr-l.yaml 中的内容复制到 rtdetr-l-HGBlock_SHSA.yaml 文件下,修改 nc 数量等于自己数据中目标的数量。

📌 模型的修改方法是将 骨干网络 中的 HGBlock模块 替换成 HGBlock_SHSA模块

# Ultralytics YOLO 🚀, AGPL-3.0 license
# RT-DETR-l object detection model with P3-P5 outputs. For details see https://docs.ultralytics.com/models/rtdetr

# Parameters
nc: 1 # number of classes
scales: # model compound scaling constants, i.e. 'model=yolov8n-cls.yaml' will call yolov8-cls.yaml with scale 'n'
  # [depth, width, max_channels]
  l: [1.00, 1.00, 1024]

backbone:
  # [from, repeats, module, args]
  - [-1, 1, HGStem, [32, 48]] # 0-P2/4
  - [-1, 6, HGBlock, [48, 128, 3]] # stage 1

  - [-1, 1, DWConv, [128, 3, 2, 1, False]] # 2-P3/8
  - [-1, 6, HGBlock, [96, 512, 3]] # stage 2

  - [-1, 1, DWConv, [512, 3, 2, 1, False]] # 4-P4/16
  - [-1, 6, HGBlock_SHSA, [192, 512, 5, True, False]] # cm, c2, k, light, shortcut
  - [-1, 6, HGBlock_SHSA, [192, 512, 5, True, True]]
  - [-1, 6, HGBlock_SHSA, [192, 512, 5, True, True]] # stage 3

  - [-1, 1, DWConv, [1024, 3, 2, 1, False]] # 8-P5/32
  - [-1, 6, HGBlock, [384, 2048, 5, True, False]] # stage 4

head:
  - [-1, 1, Conv, [256, 1, 1, None, 1, 1, False]] # 10 input_proj.2
  - [-1, 1, AIFI, [1024, 8]]
  - [-1, 1, Conv, [256, 1, 1]] # 12, Y5, lateral_convs.0

  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [7, 1, Conv, [256, 1, 1, None, 1, 1, False]] # 14 input_proj.1
  - [[-2, -1], 1, Concat, [1]]
  - [-1, 3, RepC3, [256]] # 16, fpn_blocks.0
  - [-1, 1, Conv, [256, 1, 1]] # 17, Y4, lateral_convs.1

  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [3, 1, Conv, [256, 1, 1, None, 1, 1, False]] # 19 input_proj.0
  - [[-2, -1], 1, Concat, [1]] # cat backbone P4
  - [-1, 3, RepC3, [256]] # X3 (21), fpn_blocks.1

  - [-1, 1, Conv, [256, 3, 2]] # 22, downsample_convs.0
  - [[-1, 17], 1, Concat, [1]] # cat Y4
  - [-1, 3, RepC3, [256]] # F4 (24), pan_blocks.0

  - [-1, 1, Conv, [256, 3, 2]] # 25, downsample_convs.1
  - [[-1, 12], 1, Concat, [1]] # cat Y5
  - [-1, 3, RepC3, [256]] # F5 (27), pan_blocks.1

  - [[21, 24, 27], 1, RTDETRDecoder, [nc]] # Detect(P3, P4, P5)


七、成功运行结果

打印网络模型可以看到 HSA HGBlock_SHSA 已经加入到模型中,并可以进行训练了。

rtdetr-l-SHSA

rtdetr-l-SHSA summary: 686 layers, 32,565,955 parameters, 32,565,955 gradients, 107.8 GFLOPs

                   from  n    params  module                                       arguments                     
  0                  -1  1     25248  ultralytics.nn.modules.block.HGStem          [3, 32, 48]                   
  1                  -1  6    155072  ultralytics.nn.modules.block.HGBlock         [48, 48, 128, 3, 6]           
  2                  -1  1      1408  ultralytics.nn.modules.conv.DWConv           [128, 128, 3, 2, 1, False]    
  3                  -1  6    839296  ultralytics.nn.modules.block.HGBlock         [128, 96, 512, 3, 6]          
  4                  -1  1      5632  ultralytics.nn.modules.conv.DWConv           [512, 512, 3, 2, 1, False]    
  5                  -1  6   1695360  ultralytics.nn.modules.block.HGBlock         [512, 192, 1024, 5, 6, True, False]
  6                  -1  6   2055808  ultralytics.nn.modules.block.HGBlock         [1024, 192, 1024, 5, 6, True, True]
  7                  -1  6   2055808  ultralytics.nn.modules.block.HGBlock         [1024, 192, 1024, 5, 6, True, True]
  8                  -1  1     11264  ultralytics.nn.modules.conv.DWConv           [1024, 1024, 3, 2, 1, False]  
  9                  -1  6   6728448  ultralytics.nn.AddModules.SHSA.SHSA          [1024, 1024]                  
 10                  -1  1    262656  ultralytics.nn.modules.conv.Conv             [1024, 256, 1, 1, None, 1, 1, False]
 11                  -1  1    789760  ultralytics.nn.modules.transformer.AIFI      [256, 1024, 8]                
 12                  -1  1     66048  ultralytics.nn.modules.conv.Conv             [256, 256, 1, 1]              
 13                  -1  1         0  torch.nn.modules.upsampling.Upsample         [None, 2, 'nearest']          
 14                   7  1    262656  ultralytics.nn.modules.conv.Conv             [1024, 256, 1, 1, None, 1, 1, False]
 15            [-2, -1]  1         0  ultralytics.nn.modules.conv.Concat           [1]                           
 16                  -1  3   2232320  ultralytics.nn.modules.block.RepC3           [512, 256, 3]                 
 17                  -1  1     66048  ultralytics.nn.modules.conv.Conv             [256, 256, 1, 1]              
 18                  -1  1         0  torch.nn.modules.upsampling.Upsample         [None, 2, 'nearest']          
 19                   3  1    131584  ultralytics.nn.modules.conv.Conv             [512, 256, 1, 1, None, 1, 1, False]
 20            [-2, -1]  1         0  ultralytics.nn.modules.conv.Concat           [1]                           
 21                  -1  3   2232320  ultralytics.nn.modules.block.RepC3           [512, 256, 3]                 
 22                  -1  1    590336  ultralytics.nn.modules.conv.Conv             [256, 256, 3, 2]              
 23            [-1, 17]  1         0  ultralytics.nn.modules.conv.Concat           [1]                           
 24                  -1  3   2232320  ultralytics.nn.modules.block.RepC3           [512, 256, 3]                 
 25                  -1  1    590336  ultralytics.nn.modules.conv.Conv             [256, 256, 3, 2]              
 26            [-1, 12]  1         0  ultralytics.nn.modules.conv.Concat           [1]                           
 27                  -1  3   2232320  ultralytics.nn.modules.block.RepC3           [512, 256, 3]                 
 28        [21, 24, 27]  1   7303907  ultralytics.nn.modules.head.RTDETRDecoder    [1, [256, 256, 256]]          
rtdetr-l-SHSA summary: 686 layers, 32,565,955 parameters, 32,565,955 gradients, 107.8 GFLOPs

rtdetr-l-HGBlock_SHSA

rtdetr-l-HGBlock_SHSA summary: 712 layers, 30,290,179 parameters, 30,290,179 gradients, 99.9 GFLOPs

                   from  n    params  module                                       arguments                     
  0                  -1  1     25248  ultralytics.nn.modules.block.HGStem          [3, 32, 48]                   
  1                  -1  6    155072  ultralytics.nn.modules.block.HGBlock         [48, 48, 128, 3, 6]           
  2                  -1  1      1408  ultralytics.nn.modules.conv.DWConv           [128, 128, 3, 2, 1, False]    
  3                  -1  6    839296  ultralytics.nn.modules.block.HGBlock         [128, 96, 512, 3, 6]          
  4                  -1  1      5632  ultralytics.nn.modules.conv.DWConv           [512, 512, 3, 2, 1, False]    
  5                  -1  6   1140032  ultralytics.nn.AddModules.SHSA.HGBlock_SHSA  [512, 192, 512, 5, 6, True, False]
  6                  -1  6   1140032  ultralytics.nn.AddModules.SHSA.HGBlock_SHSA  [512, 192, 512, 5, 6, True, True]
  7                  -1  6   1140032  ultralytics.nn.AddModules.SHSA.HGBlock_SHSA  [512, 192, 512, 5, 6, True, True]
  8                  -1  1     11264  ultralytics.nn.modules.conv.DWConv           [512, 1024, 3, 2, 1, False]   
  9                  -1  6   6708480  ultralytics.nn.modules.block.HGBlock         [1024, 384, 2048, 5, 6, True, False]
 10                  -1  1    524800  ultralytics.nn.modules.conv.Conv             [2048, 256, 1, 1, None, 1, 1, False]
 11                  -1  1    789760  ultralytics.nn.modules.transformer.AIFI      [256, 1024, 8]                
 12                  -1  1     66048  ultralytics.nn.modules.conv.Conv             [256, 256, 1, 1]              
 13                  -1  1         0  torch.nn.modules.upsampling.Upsample         [None, 2, 'nearest']          
 14                   7  1    131584  ultralytics.nn.modules.conv.Conv             [512, 256, 1, 1, None, 1, 1, False]
 15            [-2, -1]  1         0  ultralytics.nn.modules.conv.Concat           [1]                           
 16                  -1  3   2232320  ultralytics.nn.modules.block.RepC3           [512, 256, 3]                 
 17                  -1  1     66048  ultralytics.nn.modules.conv.Conv             [256, 256, 1, 1]              
 18                  -1  1         0  torch.nn.modules.upsampling.Upsample         [None, 2, 'nearest']          
 19                   3  1    131584  ultralytics.nn.modules.conv.Conv             [512, 256, 1, 1, None, 1, 1, False]
 20            [-2, -1]  1         0  ultralytics.nn.modules.conv.Concat           [1]                           
 21                  -1  3   2232320  ultralytics.nn.modules.block.RepC3           [512, 256, 3]                 
 22                  -1  1    590336  ultralytics.nn.modules.conv.Conv             [256, 256, 3, 2]              
 23            [-1, 17]  1         0  ultralytics.nn.modules.conv.Concat           [1]                           
 24                  -1  3   2232320  ultralytics.nn.modules.block.RepC3           [512, 256, 3]                 
 25                  -1  1    590336  ultralytics.nn.modules.conv.Conv             [256, 256, 3, 2]              
 26            [-1, 12]  1         0  ultralytics.nn.modules.conv.Concat           [1]                           
 27                  -1  3   2232320  ultralytics.nn.modules.block.RepC3           [512, 256, 3]                 
 28        [21, 24, 27]  1   7303907  ultralytics.nn.modules.head.RTDETRDecoder    [1, [256, 256, 256]]          
rtdetr-l-HGBlock_SHSA summary: 712 layers, 30,290,179 parameters, 30,290,179 gradients, 99.9 GFLOPs