spp.py 917 B

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  1. import torch
  2. import torch.nn as nn
  3. from ..basic.conv import ConvModule
  4. # Spatial Pyramid Pooling - Fast (SPPF) layer for YOLOv5 by Glenn Jocher
  5. class SPPF(nn.Module):
  6. """
  7. This code referenced to https://github.com/ultralytics/yolov5
  8. """
  9. def __init__(self, in_dim, out_dim, expand_ratio=0.5, pooling_size=5, act_type="relu", norm_type="BN"):
  10. super().__init__()
  11. inter_dim = int(in_dim * expand_ratio)
  12. self.out_dim = out_dim
  13. self.cv1 = ConvModule(in_dim, inter_dim, k=1, act_type=act_type, norm_type=norm_type)
  14. self.cv2 = ConvModule(inter_dim * 4, out_dim, k=1, act_type=act_type, norm_type=norm_type)
  15. self.m = nn.MaxPool2d(kernel_size=pooling_size, stride=1, padding=pooling_size // 2)
  16. def forward(self, x):
  17. x = self.cv1(x)
  18. y1 = self.m(x)
  19. y2 = self.m(y1)
  20. return self.cv2(torch.cat((x, y1, y2, self.m(y2)), 1))