我有一个PyTorch模型，我正在尝试通过执行前向传递来对其进行测试。这是代码：
class ResBlock(nn.Module):
def __init__(self, inplanes, planes, stride=1):
super(ResBlock, self).__init__()
self.conv1x1 = nn.Conv2d(inplanes, planes, kernel_size=1, stride=1, bias=False)
self.conv1 = nn.Conv2d(inplanes, planes, kernel_size=3, stride=stride, padding=1, bias=False)
#batch normalization
self.bn1 = nn.BatchNorm2d(planes)
self.relu = nn.ReLU()
self.conv2 = nn.Conv2d(planes, planes, kernel_size=3, stride=stride, padding=1, bias=False)
self.bn2 = nn.BatchNorm2d(planes)
self.stride = stride
def forward(self, x):
residual = self.conv1x1(x)
out = self.conv1(x)
out = self.bn1(out)
out = self.relu(out)
out = self.conv2(out)
out = self.bn2(out)
#adding the skip connection
out += residual
out = self.relu(out)
return out
class ResUnet (nn.Module):
def __init__(self, in_shape, num_classes):
super(ResUnet, self).__init__()
in_channels, height, width = in_shape
#
#self.L1 = IncResBlock(in_channels,64)
self.e1 = nn.Sequential(
nn.Conv2d(in_channels, 64, kernel_size=4, stride=2,padding=1),
ResBlock(64,64))
self.e2 = nn.Sequential(
nn.LeakyReLU(0.2,),
nn.Conv2d(64, 128, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(128),
ResBlock(128,128))
#
self.e2add = nn.Sequential(
nn.Conv2d(128, 128, kernel_size=3, stride=1,padding=1),
nn.BatchNorm2d(128))
#
##
self.e3 = nn.Sequential(
nn.LeakyReLU(0.2,inplace=True),
nn.Conv2d(128, 128, kernel_size=3, stride=1,padding=1),
nn.BatchNorm2d(128),
nn.LeakyReLU(0.2,),
nn.Conv2d(128,256, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(256),
ResBlock(256,256))
self.e4 = nn.Sequential(
nn.LeakyReLU(0.2,),
nn.Conv2d(256,512, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(512),
ResBlock(512,512))
#
self.e4add = nn.Sequential(
nn.Conv2d(512,512, kernel_size=3, stride=1,padding=1),
nn.BatchNorm2d(512))
#
self.e5 = nn.Sequential(
nn.LeakyReLU(0.2,inplace=True),
nn.Conv2d(512,512, kernel_size=3, stride=1,padding=1),
nn.BatchNorm2d(512),
nn.LeakyReLU(0.2,),
nn.Conv2d(512,512, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(512),
ResBlock(512,512))
#
#
self.e6 = nn.Sequential(
nn.LeakyReLU(0.2,),
nn.Conv2d(512,512, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(512),
ResBlock(512,512))
#
self.e6add = nn.Sequential(
nn.Conv2d(512,512, kernel_size=3, stride=1,padding=1),
nn.BatchNorm2d(512))
#
self.e7 = nn.Sequential(
nn.LeakyReLU(0.2,inplace=True),
nn.Conv2d(512,512, kernel_size=3, stride=1,padding=1),
nn.BatchNorm2d(512),
nn.LeakyReLU(0.2,),
nn.Conv2d(512,512, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(512),
ResBlock(512,512))
#
self.e8 = nn.Sequential(
nn.LeakyReLU(0.2,),
nn.Conv2d(512,512, kernel_size=4, stride=2,padding=1))
#nn.BatchNorm2d(512))
self.d1 = nn.Sequential(
nn.ReLU(),
nn.ConvTranspose2d(512, 512, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(512),
nn.Dropout(p=0.5),
ResBlock(512,512))
#
self.d2 = nn.Sequential(
nn.ReLU(),
nn.ConvTranspose2d(1024, 512, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(512),
nn.Dropout(p=0.5),
ResBlock(512,512))
#
self.d3 = nn.Sequential(
nn.ReLU(),
nn.ConvTranspose2d(1024, 512, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(512),
nn.Dropout(p=0.5),
ResBlock(512,512))
#
self.d4 = nn.Sequential(
nn.ReLU(),
nn.ConvTranspose2d(1024, 512, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(512),
ResBlock(512,512))
#
self.d5 = nn.Sequential(
nn.ReLU(),
nn.ConvTranspose2d(1024, 256, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(256),
ResBlock(256,256))
#
self.d6 = nn.Sequential(
nn.ReLU(),
nn.ConvTranspose2d(512, 128, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(128),
ResBlock(128,128))
#
self.d7 = nn.Sequential(
nn.ReLU(),
nn.ConvTranspose2d(256, 64, kernel_size=4, stride=2,padding=1),
nn.BatchNorm2d(64),
ResBlock(64,64))
#
self.d8 = nn.Sequential(
nn.ReLU(),
nn.ConvTranspose2d(128, 64, kernel_size=4, stride=2,padding=1))
#nn.BatchNorm2d(64),
#nn.ReLU())
self.out_l = nn.Sequential(
nn.Conv2d(64,num_classes,kernel_size=1,stride=1))
#nn.ReLU())
def forward(self, x):
#Image Encoder
#### Encoder #####
en1 = self.e1(x)
en2 = self.e2(en1)
en2add = self.e2add(en2)
en3 = self.e3(en2add)
en4 = self.e4(en3)
en4add = self.e4add(en4)
en5 = self.e5(en4add)
en6 = self.e6(en5)
en6add = self.e6add(en6)
en7 = self.e7(en6add)
en8 = self.e8(en7)
#### Decoder ####
de1_ = self.d1(en8)
de1 = torch.cat([en7,de1_],1)
de2_ = self.d2(de1)
de2 = torch.cat([en6add,de2_],1)
de3_ = self.d3(de2)
de3 = torch.cat([en5,de3_],1)
de4_ = self.d4(de3)
de4 = torch.cat([en4add,de4_],1)
de5_ = self.d5(de4)
de5 = torch.cat([en3,de5_],1)
de6_ = self.d6(de5)
de6 = torch.cat([en2add,de6_],1)
de7_ = self.d7(de6)
de7 = torch.cat([en1,de7_],1)
de8 = self.d8(de7)
out_l_mask = self.out_l(de8)
return out_l_mask
这是我尝试测试的方式：
modl = ResUnet((1,512,512), 1)
x = torch.rand(1, 1, 512, 512)
modl(x)
这很好用，对于64倍数的任何大小也一样。
如果我尝试：
modl = ResUnet((1,320,320), 1)
x = torch.rand(1, 1, 320, 320)
modl(x)
它抛出一个错误
---------------------------------------------------------------------------
RuntimeError Traceback (most recent call last)
<ipython-input-46-4ddc821c365b> in <module>
----> 1 modl(x)
~/.conda/envs/torch0.4/lib/python3.6/site-packages/torch/nn/modules/module.py in __call__(self, *input, **kwargs)
475 result = self._slow_forward(*input, **kwargs)
476 else:
--> 477 result = self.forward(*input, **kwargs)
478 for hook in self._forward_hooks.values():
479 hook_result = hook(self, input, result)
<ipython-input-36-f9eeefa3c0b8> in forward(self, x)
221 de2_ = self.d2(de1)
222 #print de2_.size()
--> 223 de2 = torch.cat([en6add,de2_],1)
224 #print de2.size()
225
RuntimeError: invalid argument 0: Sizes of tensors must match except in dimension 1. Got 5 and 4 in dimension 2 at /opt/conda/conda-bld/pytorch_1535491974311/work/aten/src/TH/generic/THTensorMath.cpp:3616
我认为问题是由于输入大小不是2的幂而引起的，但是我不确定如何针对给定的输入量（320，320）进行纠正。
答案 0 :(得分：0)
此问题源于下采样（编码器）路径和上采样（解码器）路径中的变量大小不匹配。您的代码庞大且难以理解，但是通过插入print语句，我们可以检查
en6add的大小为[1, 512, 5, 5] en7是[1, 512, 2, 2] en8是[1, 512, 1, 1] de1_是[1, 512, 2, 2] de1 [1, 1024, 2, 2] de2_ [1, 512, 4, 4] 此时，您尝试将其与en6add进行连接，因此显然创建de2_的代码不够“充分采样”。我的强烈猜测是，您需要注意nn.ConvTranspose2d的output_padding参数，并可能在几个地方将其设置为1。我会尽力为您修复此错误，但该示例距离minimal太远，以至于我无法全神贯注。