266 lines
11 KiB
Python
266 lines
11 KiB
Python
# models/rord.py
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import torch
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import torch.nn as nn
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import torch.nn.functional as F
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from torchvision import models
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# --- Optional Attention Modules (default disabled) ---
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class SEBlock(nn.Module):
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def __init__(self, channels: int, reduction: int = 16):
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super().__init__()
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self.avg_pool = nn.AdaptiveAvgPool2d(1)
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hidden = max(1, channels // reduction)
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self.fc = nn.Sequential(
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nn.Linear(channels, hidden, bias=False),
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nn.ReLU(inplace=True),
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nn.Linear(hidden, channels, bias=False),
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nn.Sigmoid(),
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)
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def forward(self, x: torch.Tensor) -> torch.Tensor:
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b, c, _, _ = x.shape
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y = self.avg_pool(x).view(b, c)
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y = self.fc(y).view(b, c, 1, 1)
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return x * y
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class CBAM(nn.Module):
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def __init__(self, channels: int, reduction: int = 16, spatial_kernel: int = 7):
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super().__init__()
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hidden = max(1, channels // reduction)
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# Channel attention (MLP on pooled features)
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self.mlp = nn.Sequential(
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nn.Linear(channels, hidden, bias=False),
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nn.ReLU(inplace=True),
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nn.Linear(hidden, channels, bias=False),
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)
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# Spatial attention
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padding = spatial_kernel // 2
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self.spatial = nn.Conv2d(2, 1, kernel_size=spatial_kernel, padding=padding, bias=False)
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def forward(self, x: torch.Tensor) -> torch.Tensor:
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b, c, _, _ = x.shape
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avg = torch.mean(x, dim=(2, 3))
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mx, _ = torch.max(torch.max(x, dim=2).values, dim=2)
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ch = torch.sigmoid(self.mlp(avg) + self.mlp(mx))
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ch = ch.view(b, c, 1, 1)
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x = x * ch
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avg_out = torch.mean(x, dim=1, keepdim=True)
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max_out, _ = torch.max(x, dim=1, keepdim=True)
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attn = torch.sigmoid(self.spatial(torch.cat([avg_out, max_out], dim=1)))
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return x * attn
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class RoRD(nn.Module):
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def __init__(self, fpn_out_channels: int = 256, fpn_levels=(2, 3, 4), cfg=None):
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"""
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修复后的 RoRD 模型。
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- 实现了共享骨干网络，以提高计算效率和减少内存占用。
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- 确保检测头和描述子头使用相同尺寸的特征图。
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- 新增（可选）FPN 推理路径，提供多尺度特征用于高效匹配。
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"""
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super(RoRD, self).__init__()
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# 解析可选配置（保持全部默认关闭）
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backbone_name = "vgg16"
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pretrained = False
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attn_enabled = False
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attn_type = "none"
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attn_places = []
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attn_reduction = 16
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attn_spatial_kernel = 7
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try:
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if cfg is not None and hasattr(cfg, 'model'):
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m = cfg.model
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if hasattr(m, 'backbone'):
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backbone_name = str(getattr(m.backbone, 'name', backbone_name))
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pretrained = bool(getattr(m.backbone, 'pretrained', pretrained))
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if hasattr(m, 'attention'):
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attn_enabled = bool(getattr(m.attention, 'enabled', attn_enabled))
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attn_type = str(getattr(m.attention, 'type', attn_type))
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attn_places = list(getattr(m.attention, 'places', attn_places))
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attn_reduction = int(getattr(m.attention, 'reduction', attn_reduction))
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attn_spatial_kernel = int(getattr(m.attention, 'spatial_kernel', attn_spatial_kernel))
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except Exception:
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# 配置非标准时，保留默认
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pass
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# 构建骨干
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self.backbone_name = backbone_name
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out_channels_backbone = 512
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# 默认各层通道（VGG 对齐）
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c2_ch, c3_ch, c4_ch = 128, 256, 512
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if backbone_name == "resnet34":
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res = models.resnet34(weights=models.ResNet34_Weights.DEFAULT if pretrained else None)
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self.backbone = nn.Sequential(
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res.conv1, res.bn1, res.relu, res.maxpool,
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res.layer1, res.layer2, res.layer3, res.layer4,
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)
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# 记录原始模型以备进一步扩展（如中间层 hook）
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self._backbone_raw = res
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out_channels_backbone = 512
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# 选择 layer2/layer3/layer4 作为 C2/C3/C4
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c2_ch, c3_ch, c4_ch = 128, 256, 512
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elif backbone_name == "efficientnet_b0":
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eff = models.efficientnet_b0(weights=models.EfficientNet_B0_Weights.DEFAULT if pretrained else None)
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self.backbone = eff.features
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self._backbone_raw = eff
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out_channels_backbone = 1280
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# 选择 features[2]/[3]/[6] 作为 C2/C3/C4（约 24/40/192）
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c2_ch, c3_ch, c4_ch = 24, 40, 192
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else:
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vgg16_features = models.vgg16(weights=models.VGG16_Weights.DEFAULT if pretrained else None).features
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# VGG16 特征各阶段索引（conv & relu 层序列）
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# relu2_2 索引 8，relu3_3 索引 15，relu4_3 索引 22
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self.features = vgg16_features
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# 共享骨干（向后兼容单尺度路径，使用到 relu4_3）
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self.backbone = nn.Sequential(*list(vgg16_features.children())[:23])
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out_channels_backbone = 512
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c2_ch, c3_ch, c4_ch = 128, 256, 512
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# 非 VGG 情况下，确保属性存在（供 _extract_c234 判断）
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if backbone_name != "vgg16":
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self.features = None
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# 检测头
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self.detection_head = nn.Sequential(
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nn.Conv2d(out_channels_backbone, 256, kernel_size=3, padding=1),
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nn.ReLU(inplace=True),
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nn.Conv2d(256, 128, kernel_size=3, padding=1),
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nn.ReLU(inplace=True),
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nn.Conv2d(128, 1, kernel_size=1),
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nn.Sigmoid()
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)
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# 描述子头
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self.descriptor_head = nn.Sequential(
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nn.Conv2d(out_channels_backbone, 256, kernel_size=3, padding=1),
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nn.ReLU(inplace=True),
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nn.Conv2d(256, 128, kernel_size=3, padding=1),
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nn.ReLU(inplace=True),
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nn.Conv2d(128, 128, kernel_size=1),
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nn.InstanceNorm2d(128)
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)
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# 注意力包装（默认关闭）
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def make_attn_layer(in_channels: int) -> nn.Module:
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if not attn_enabled or attn_type == "none":
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return nn.Identity()
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if attn_type == "cbam":
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return CBAM(in_channels, reduction=attn_reduction, spatial_kernel=attn_spatial_kernel)
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return SEBlock(in_channels, reduction=attn_reduction)
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self._attn_backbone_high = make_attn_layer(out_channels_backbone) if "backbone_high" in attn_places else nn.Identity()
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if "det_head" in attn_places:
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self.detection_head = nn.Sequential(make_attn_layer(out_channels_backbone), *list(self.detection_head.children()))
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if "desc_head" in attn_places:
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self.descriptor_head = nn.Sequential(make_attn_layer(out_channels_backbone), *list(self.descriptor_head.children()))
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# --- FPN 组件（用于可选多尺度推理） ---
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self.fpn_out_channels = fpn_out_channels
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self.fpn_levels = tuple(sorted(set(fpn_levels))) # e.g., (2,3,4)
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# 横向连接 1x1：根据骨干动态对齐到相同通道数
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self.lateral_c2 = nn.Conv2d(c2_ch, fpn_out_channels, kernel_size=1)
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self.lateral_c3 = nn.Conv2d(c3_ch, fpn_out_channels, kernel_size=1)
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self.lateral_c4 = nn.Conv2d(c4_ch, fpn_out_channels, kernel_size=1)
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# 平滑 3x3 conv
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self.smooth_p2 = nn.Conv2d(fpn_out_channels, fpn_out_channels, kernel_size=3, padding=1)
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self.smooth_p3 = nn.Conv2d(fpn_out_channels, fpn_out_channels, kernel_size=3, padding=1)
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self.smooth_p4 = nn.Conv2d(fpn_out_channels, fpn_out_channels, kernel_size=3, padding=1)
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# 共享的 FPN 检测/描述子头（输入通道为 fpn_out_channels）
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self.det_head_fpn = nn.Sequential(
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nn.Conv2d(fpn_out_channels, 128, kernel_size=3, padding=1),
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nn.ReLU(inplace=True),
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nn.Conv2d(128, 1, kernel_size=1),
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nn.Sigmoid(),
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)
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self.desc_head_fpn = nn.Sequential(
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nn.Conv2d(fpn_out_channels, 128, kernel_size=3, padding=1),
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nn.ReLU(inplace=True),
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nn.Conv2d(128, 128, kernel_size=1),
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nn.InstanceNorm2d(128),
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)
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def forward(self, x: torch.Tensor, return_pyramid: bool = False):
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if not return_pyramid:
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# 向后兼容的单尺度路径（relu4_3）
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features = self.backbone(x)
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# 可选：骨干高层注意力
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features = self._attn_backbone_high(features)
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detection_map = self.detection_head(features)
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descriptors = self.descriptor_head(features)
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return detection_map, descriptors
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# --- FPN 路径：提取 C2/C3/C4 ---
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c2, c3, c4 = self._extract_c234(x)
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# 根据骨干设置各层对应的下采样步幅（相对输入）
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if self.backbone_name == "vgg16":
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s2, s3, s4 = 2, 4, 8
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elif self.backbone_name == "resnet34":
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s2, s3, s4 = 8, 16, 32
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elif self.backbone_name == "efficientnet_b0":
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s2, s3, s4 = 4, 8, 32
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else:
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s2 = s3 = s4 = 8 # 合理保守默认
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p4 = self.lateral_c4(c4)
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p3 = self.lateral_c3(c3) + F.interpolate(p4, size=c3.shape[-2:], mode="nearest")
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p2 = self.lateral_c2(c2) + F.interpolate(p3, size=c2.shape[-2:], mode="nearest")
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p4 = self.smooth_p4(p4)
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p3 = self.smooth_p3(p3)
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p2 = self.smooth_p2(p2)
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pyramid = {}
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if 4 in self.fpn_levels:
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pyramid["P4"] = (self.det_head_fpn(p4), self.desc_head_fpn(p4), s4)
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if 3 in self.fpn_levels:
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pyramid["P3"] = (self.det_head_fpn(p3), self.desc_head_fpn(p3), s3)
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if 2 in self.fpn_levels:
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pyramid["P2"] = (self.det_head_fpn(p2), self.desc_head_fpn(p2), s2)
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return pyramid
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def _extract_c234(self, x: torch.Tensor):
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"""提取中间层特征 C2/C3/C4，适配不同骨干。"""
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if self.backbone_name == "vgg16":
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c2 = c3 = c4 = None
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for i, layer in enumerate(self.features):
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x = layer(x)
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if i == 8: # relu2_2
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c2 = x
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elif i == 15: # relu3_3
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c3 = x
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elif i == 22: # relu4_3
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c4 = x
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break
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assert c2 is not None and c3 is not None and c4 is not None
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return c2, c3, c4
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if self.backbone_name == "resnet34":
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res = self._backbone_raw
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x = res.conv1(x)
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x = res.bn1(x)
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x = res.relu(x)
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x = res.maxpool(x)
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x = res.layer1(x)
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c2 = res.layer2(x) # 128
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c3 = res.layer3(c2) # 256
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c4 = res.layer4(c3) # 512
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return c2, c3, c4
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if self.backbone_name == "efficientnet_b0":
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# 取 features[2]/[3]/[6] 作为 C2/C3/C4
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feats = self._backbone_raw.features
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c2 = c3 = c4 = None
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x = feats[0](x) # stem
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x = feats[1](x)
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x = feats[2](x); c2 = x
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x = feats[3](x); c3 = x
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x = feats[4](x)
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x = feats[5](x)
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x = feats[6](x); c4 = x
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return c2, c3, c4
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raise RuntimeError(f"Unsupported backbone for FPN: {self.backbone_name}") |