RuntimeError:给定groups=1，权重为[64，3，3，3]，期望输入[4,5000,5000，3]有3个通道，但实际得到5000个通道

Question

所以，我有一个U-Net模型，我将5000x5000x3的图像输入到模型中，然后我得到了上面的错误。

这是我的模型。

import torch
import torch.nn as nn


def double_conv(in_channels, out_channels):
    return nn.Sequential(
        nn.Conv2d(in_channels, out_channels, 3, padding=1),
        nn.ReLU(inplace=True),
        nn.Conv2d(out_channels, out_channels, 3, padding=1),
        nn.ReLU(inplace=True)
    )


class UNeT(nn.Module):
    def __init__(self, n_class):
        super().__init__()
        self.dconv_down1 = double_conv(3, 64)
        self.dconv_down2 = double_conv(64, 128)
        self.dconv_down3 = double_conv(128, 256)
        self.dconv_down4 = double_conv(256, 512)
        self.maxpool = nn.MaxPool2d(2)
        self.upsample = nn.Upsample(scale_factor=2, mode='bilinear',
                                    align_corners=True)
        self.dconv_up3 = double_conv(256 + 512, 256)
        self.dconv_up2 = double_conv(128 + 256, 128)
        self.dconv_up1 = double_conv(128 + 64, 64)
        self.conv_last = nn.Conv2d(64, n_class, 1)

    def forward(self, x):
        conv1 = self.dconv_down1(x)
        x = self.maxpool(conv1)
        conv2 = self.dconv_down2(x)
        x = self.maxpool(conv2)
        conv3 = self.dconv_down3(x)
        x = self.maxpool(conv3)
        x = self.dconv_down4(x)
        x = self.upsample(x)
        x = torch.cat([x, conv3], dim=1)
        x = self.dconv_up3(x)
        x = self.upsample(x)
        x = torch.cat([x, conv2], dim=1)
        x = self.dconv_up2(x)
        x = self.upsample(x)
        x = torch.cat([x, conv1], dim=1)
        x = self.dconv_up1(x)
        out = self.conv_last(x)
        return out

我试图做模型(inputs.unsqueeze_(0))，但我得到了一个不同的错误。

Answer 1

pytorch中的维度顺序与您预期的不同。您的输入张量具有4x5000x5000x3的shape，您将其解释为一批大小的4，具有5000x5000像素的图像，每个像素有3个通道。也就是说，您的维度是batch-height-width-channel.

然而，pytorch预计张量维度将以不同的顺序出现：batch-channel-height-width.也就是说，channel维度应该在宽度和高度空间维度之前。

您需要permute输入张量的维度来解决您的问题：

model(inputs.permute(0, 3, 1, 2))

有关更多信息，请参阅nn.Conv2d的文档。