DCGAN---生成动漫头像

数据集

kaggle：https://www.kaggle.com/datasets/soumikrakshit/anime-faces

代码

import torch
import torch.nn as nn
import torch.nn.functional as F
import matplotlib.pyplot as plt
from torch.utils import data
from torchvision import transforms
import glob
from PIL import Image


# glob获取全部图像的路径
imgs_path = glob.glob(r'anime-faces/*.png')

# 画6张看看
# plt.figure(figsize=(12, 8))
# for i, img_path in enumerate(imgs_path[:6]):
#     img = np.array(Image.open(img_path))
#     plt.subplot(2, 3, i+1)
#     plt.imshow(img)
#     print(img.shape)
# plt.show()

# GAN 输入-1，1 便于训练
transform = transforms.Compose([
    transforms.ToTensor(),
    transforms.Normalize(0.5, 0.5),  # 数据减均值除方差
])


# 创建数据集
class Face_dataset(data.Dataset):
    def __init__(self, imgs_path):
        self.imgs_path = imgs_path

    def __getitem__(self, index):
        img_path = self.imgs_path[index]
        pil_img = Image.open(img_path)
        pil_img = transform(pil_img)
        return pil_img

    def __len__(self):
        return len(self.imgs_path)


dataset = Face_dataset(imgs_path)
dataloader = data.DataLoader(dataset,
                             batch_size=32,
                             shuffle=True)
imgs_batch = next(iter(dataloader))  # 32,3,64,64

# 画出来看看
plt.figure(figsize=(12, 8))
for i, img in enumerate(imgs_batch[:6]):
    img = (img.permute(1, 2, 0).numpy() + 1) / 2  # 64,64,3
    plt.subplot(2, 3, i+1)
    plt.imshow(img)
plt.show()


# 定义生成器，依然输入长度100的噪声
class Generator(nn.Module):
    def __init__(self):
        super(Generator, self).__init__()
        self.linear1 = nn.Linear(100, 256*16*16)
        self.bn1 = nn.BatchNorm1d(256*16*16)
        self.deconv1 = nn.ConvTranspose2d(256, 128, kernel_size=(3, 3), stride=1, padding=1)
        self.bn2 = nn.BatchNorm2d(128)
        self.deconv2 = nn.ConvTranspose2d(128, 64, kernel_size=(4, 4), stride=2, padding=1)
        self.bn3 = nn.BatchNorm2d(64)
        self.deconv3 = nn.ConvTranspose2d(64, 3, kernel_size=(4, 4), stride=2, padding=1)

    def forward(self, x):
        x = F.relu(self.linear1(x))
        x = self.bn1(x)
        x = x.view(-1, 256, 16, 16)
        x = F.relu(self.deconv1(x))
        x = self.bn2(x)
        x = F.relu(self.deconv2(x))
        x = self.bn3(x)
        x = torch.tanh(self.deconv3(x))
        return x


# 判别器,输入（64, 64）图片
class Discriminator(nn.Module):
    def __init__(self):
        super(Discriminator, self).__init__()
        self.conv1 = nn.Conv2d(3, 64, kernel_size=3, stride=2)  # (64, 31, 31)
        self.conv2 = nn.Conv2d(64, 128, 3, 2)
        self.bn = nn.BatchNorm2d(128)  # 128 * 15 * 15
        self.fc = nn.Linear(128*15*15, 1)

    def forward(self, x):
        x = F.dropout2d(F.leaky_relu(self.conv1(x)), p=0.3)
        x = F.dropout2d(F.leaky_relu(self.conv2(x)), p=0.3)
        x = self.bn(x)
        x = x.view(-1, 128*15*15)
        x = torch.sigmoid(self.fc(x))
        return x


device = 'cuda' if torch.cuda.is_available() else 'cpu'
if device == 'cuda':
    print('using cuda:', torch.cuda.get_device_name(0))
else:
    print(device)

Gen = Generator().to(device)
Dis = Discriminator().to(device)

loss_fun = nn.BCELoss()
d_optimizer = torch.optim.Adam(Dis.parameters(), lr=1e-5)  # 小技巧
g_optimizer = torch.optim.Adam(Gen.parameters(), lr=1e-4)


def generate_and_save_image(model, test_input):
    predictions = model(test_input).permute(0, 2, 3, 1).cpu().numpy()
    # fig = plt.figure(figsize=(40, 80))  # 画布设置太大会导致错误
    for i in range(predictions.shape[0]):
        plt.subplot(2, 4, i+1)
        plt.imshow((predictions[i]+1) / 2)
        plt.axis('off')
    plt.show()


test_seed = torch.randn(8, 100, device=device)
D_loss = []
G_loss = []

for epoch in range(500):
    d_epoch_loss = 0
    g_epoch_loss = 0
    count = len(dataloader)  # 批次数
    for step, img in enumerate(dataloader):
        img = img.to(device)
        size = img.size(0)
        random_noise = torch.randn(size, 100, device=device)

        d_optimizer.zero_grad()
        real_output = Dis(img)  # 判别器输入真实图片
        # 判别器在真实图像上的损失
        d_real_loss = loss_fun(real_output,
                                    torch.ones_like(real_output)
                                    )
        d_real_loss.backward()

        gen_img = Gen(random_noise)
        fake_output = Dis(gen_img.detach())  # 判别器输入生成图片,fake_output对生成图片的预测
        # gen_img是由生成器得来的，但我们现在只对判别器更新，所以要截断对Gen的更新
        # detach()得到了没有梯度的tensor，求导到这里就停止了，backward的时候就不会求导到Gen了

        d_fake_loss = loss_fun(fake_output,
                                    torch.zeros_like(fake_output)
                                    )
        d_fake_loss.backward()
        d_loss = d_real_loss + d_fake_loss
        d_optimizer.step()

        # 更新生成器
        g_optimizer.zero_grad()
        fake_output = Dis(gen_img)
        g_loss = loss_fun(fake_output,
                               torch.ones_like(fake_output))
        g_loss.backward()
        g_optimizer.step()

        with torch.no_grad():
            d_epoch_loss += d_loss.item()
            g_epoch_loss += g_loss.item()

    with torch.no_grad():  # 之后的内容不进行梯度的计算（图的构建）
        d_epoch_loss /= count
        g_epoch_loss /= count
        D_loss.append(d_epoch_loss)
        G_loss.append(g_epoch_loss)
        print('Epoch:', epoch+1)
        generate_and_save_image(model=Gen, test_input=test_seed)

    plt.plot(D_loss, label='D_loss')
    plt.plot(G_loss, label='G_loss')
    plt.legend()
    plt.show()

效果

跑了50轮