·自上而下:首先對C5進行1×1卷積降低通道數得到P5,然後依次進行上取樣得到P4、P3和P2,目的是得到與C4、C3與C2長寬相同的特徵,以方便下一步進行逐元素相加
Conv2d(planes,self
Module):expansion=1def__init__(self,inplanes,planes,stride=1,downsample=None):super(BasicBlock,self)
0, visual=2 stride=2)]# layers += [BasicConv(256,128,kernel_size=1,stride=1)]# layers += [BasicConv(128,256,kernel_size=
Module):expansion=4def__init__(self,inplanes,planes,stride=1,downsample=None):super(Bottleneck,self)
Conv2d(in_planes, out_planes, kernel_size=3, stride=stride,padding=1, bias=False)# 這是殘差網路中的basicblock,實現的功能如下方解釋:class B