我正在构建一个DCGAN，我的输出形状有问题，当我尝试计算BCELoss时，它与标签的形状不匹配。
为了生成鉴别器输出，我是否必须一直使用卷积，或者我可以在某个点添加一个线性层来匹配我想要的形状?
我的意思是，我是否必须通过添加更多的卷积层来减小形状或者我可以添加一个完全连接的层?我认为它应该有一个完全连接的层，但在每个教程中我检查鉴别器没有完全连接的层。
import random
import torch.nn as nn
import torch.optim as optim
import torch.utils.data
import torchvision.datasets as torch_dataset
import torchvision.transforms as transforms
import torchvision.utils as vutils
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from IPython.display import HTML
seed = 1
print("Random Seed: ", seed)
random.seed(seed)
torch.manual_seed(seed)
images_folder_path = "./spectrograms/"
batch_size = 1
image_size = 256
n_channels = 1
z_vector = 100
n_features_generator = 32
n_features_discriminator = 32
num_epochs = 5
lr = 0.0002
beta1 = 0.5
dataset = torch_dataset.ImageFolder(
root=images_folder_path, transform=transforms.Compose(
[
transforms.Grayscale(num_output_channels=1),
transforms.Resize(image_size),
transforms.CenterCrop(image_size),
transforms.ToTensor(),
transforms.Normalize(0.5, 0.5)
]
)
)
dataloader = torch.utils.data.DataLoader(dataset, batch_size=batch_size, shuffle=True, num_workers=0)
device = torch.device("cuda:0" if (torch.cuda.is_available()) else "cpu")
def weights_init(m):
classname = m.__class__.__name__
if classname.find('Conv') != -1:
nn.init.normal_(m.weight.data, 0.0, 0.02)
elif classname.find('BatchNorm') != -1:
nn.init.normal_(m.weight.data, 1.0, 0.02)
nn.init.constant_(m.bias.data, 0)
class Generator(nn.Module):
def __init__(self):
super(Generator, self).__init__()
self.main = nn.Sequential(
nn.ConvTranspose2d(z_vector, n_features_generator * 8, 4, 1, bias=False),
nn.BatchNorm2d(n_features_generator * 8),
nn.ReLU(True),
nn.ConvTranspose2d(n_features_generator * 8, n_features_generator * 4, 4, 2, 1, bias=False),
nn.BatchNorm2d(n_features_generator * 4),
nn.ReLU(True),
nn.ConvTranspose2d(n_features_generator * 4, n_features_generator * 2, 4, 2, 1, bias=False),
nn.BatchNorm2d(n_features_generator * 2),
nn.ReLU(True),
nn.ConvTranspose2d(n_features_generator * 2, n_features_generator, 4, 2, 1, bias=False),
nn.BatchNorm2d(n_features_generator),
nn.ReLU(True),
nn.ConvTranspose2d(n_features_generator, n_channels, 4, 2, 1, bias=False),
nn.Tanh()
)
def forward(self, inputs):
return self.main(inputs)
# Convolutional Layer Output Shape = [(W−K+2P)/S]+1
# W is the input volume
# K is the Kernel size
# P is the padding
# S is the stride
class Discriminator(nn.Module):
def __init__(self):
super(Discriminator, self).__init__()
self.main = nn.Sequential(
nn.Conv2d(n_channels, n_features_discriminator, 4, 2, 1, bias=False),
nn.LeakyReLU(0.2, inplace=True),
nn.Conv2d(n_features_discriminator, n_features_discriminator * 2, 4, 2, 1, bias=False),
nn.BatchNorm2d(n_features_discriminator * 2),
nn.LeakyReLU(0.2, inplace=True),
nn.Conv2d(n_features_discriminator * 2, n_features_discriminator * 4, 4, 2, 1, bias=False),
nn.BatchNorm2d(n_features_discriminator * 4),
nn.LeakyReLU(0.2, inplace=True),
nn.Conv2d(n_features_discriminator * 4, n_features_discriminator * 8, 4, 2, 1, bias=False),
nn.BatchNorm2d(n_features_discriminator * 8),
nn.LeakyReLU(0.2, inplace=True),
nn.Conv2d(n_features_discriminator * 8, 1, 4, 1, bias=False),
)
def forward(self, inputs):
return self.main(inputs)
netG = Generator().to(device)
if device.type == 'cuda':
netG = nn.DataParallel(netG)
netG.apply(weights_init)
print(netG)
netD = Discriminator().to(device)
if device.type == 'cuda':
netD = nn.DataParallel(netD)
netD.apply(weights_init)
print(netD)
criterion = nn.BCEWithLogitsLoss()
fixed_noise = torch.randn(64, z_vector, 1, 1, device=device)
real_label = 1.
fake_label = 0.
optimizerD = optim.Adam(netD.parameters(), lr=lr, betas=(beta1, 0.999))
optimizerG = optim.Adam(netG.parameters(), lr=lr, betas=(beta1, 0.999))
img_list = []
G_losses = []
D_losses = []
iters = 0
print("Starting Training Loop...")
for epoch in range(num_epochs):
for i, data in enumerate(dataloader, 0):
netD.zero_grad()
real_cpu = data[0].to(device)
b_size = real_cpu.size(0)
label = torch.full((b_size,), real_label, dtype=torch.float, device=device)
output = netD(real_cpu)
print(output.shape)
print(label.shape)
output = output.view(-1)
errD_real = criterion(output, label)
errD_real.backward()
D_x = output.mean().item()
noise = torch.randn(b_size, z_vector, 1, 1, device=device)
fake = netG(noise)
label.fill_(fake_label)
output = netD(fake.detach()).view(-1)
errD_fake = criterion(output, label)
errD_fake.backward()
D_G_z1 = output.mean().item()
errD = errD_real + errD_fake
optimizerD.step()
netG.zero_grad()
label.fill_(real_label)
output = netD(fake).view(-1)
errG = criterion(output, label)
errG.backward()
D_G_z2 = output.mean().item()
optimizerG.step()
if i % 50 == 0:
print('[%d/%d][%d/%d]tLoss_D: %.4ftLoss_G: %.4ftD(x): %.4ftD(G(z)): %.4f / %.4f'
% (epoch, num_epochs, i, len(dataloader),
errD.item(), errG.item(), D_x, D_G_z1, D_G_z2))
G_losses.append(errG.item())
D_losses.append(errD.item())
if (iters % 500 == 0) or ((epoch == num_epochs-1) and (i == len(dataloader)-1)):
with torch.no_grad():
fake = netG(fixed_noise).detach().cpu()
img_list.append(vutils.make_grid(fake, padding=2, normalize=True))
iters += 1
我得到的错误:
Traceback (most recent call last):
File "G:/Pastas Estruturadas/Conhecimento/CEFET/IA/SpectroGAN/dcgan.py", line 140, in <module>
errD_real = criterion(output, label)
File "C:UsersRamonanaconda3envsvisionlibsite-packagestorchnnmodulesmodule.py", line 722, in _call_impl
result = self.forward(*input, **kwargs)
File "C:UsersRamonanaconda3envsvisionlibsite-packagestorchnnmodulesloss.py", line 631, in forward
reduction=self.reduction)
File "C:UsersRamonanaconda3envsvisionlibsite-packagestorchnnfunctional.py", line 2538, in binary_cross_entropy_with_logits
raise ValueError("Target size ({}) must be the same as input size ({})".format(target.size(), input.size()))
ValueError: Target size (torch.Size([1])) must be the same as input size (torch.Size([169]))
输出形状:torch.Size([1, 1, 13, 13])，标签形状:torch.Size([1])。
DCGAN描述了一个具体的体系结构，其中Conv层用于特征映射的下采样。如果你仔细设计你的转换层，你可以不使用线性层，但这并不意味着当你使用线性层下采样(尤其是最后一层)时，它将不起作用。DCGAN的论文刚刚发现，使用Conv层而不是Linear层进行下采样效果更好。
如果你想要维持这种架构，你可以改变内核的大小、填充或跨距，在最后一层给你一个单一的值。参考Pytorch关于Conv层的文档，查看给定输入大小
时输出大小应该是多少。