Introduction:

I am trying to get a CDCGAN (Conditional Deep Convolutional Generative Adversarial Network) to work on the MNIST dataset which should be fairly easy considering that the library (PyTorch) I am using has a tutorial on its website.
But I can't seem to get It working it just produces garbage or the model collapses or both.

What I tried:

  • making the model Conditional semi-supervised learning
  • using batch norm
  • using dropout on each layer besides the input/output layer on the generator and discriminator
  • label smoothing to combat overconfidence
  • adding noise to the images (I guess you call this instance noise) to get a better data distribution
  • use leaky relu to avoid vanishing gradients
  • using a replay buffer to combat forgetting of learned stuff and overfitting
  • playing with hyperparameters
  • comparing it to the model from PyTorch tutorial
  • basically what I did besides some things like Embedding layer ect.

Images my Model generated:

Hyperparameters:

batch_size=50, learning_rate_discrimiantor=0.0001, learning_rate_generator=0.0003, shuffle=True, ndf=64, ngf=64, droupout=0.5
enter image description hereenter image description hereenter image description hereenter image description here

batch_size=50, learning_rate_discriminator=0.0003, learning_rate_generator=0.0003, shuffle=True, ndf=64, ngf=64, dropout=0
enter image description hereenter image description hereenter image description hereenter image description here

Images Pytorch tutorial Model generated:

Code for the pytorch tutorial dcgan model
As comparison here are the images from the DCGAN from the pytorch turoial:
enter image description hereenter image description hereenter image description here

My Code:

import torch
import torch.nn as nn
import torchvision
from torchvision import transforms, datasets
import torch.nn.functional as F
from torch import optim as optim
from torch.utils.tensorboard import SummaryWriter

import numpy as np

import os
import time


class Discriminator(torch.nn.Module):
    def __init__(self, ndf=16, dropout_value=0.5):  # ndf feature map discriminator
        super().__init__()
        self.ndf = ndf
        self.droupout_value = dropout_value

        self.condi = nn.Sequential(
            nn.Linear(in_features=10, out_features=64 * 64)
        )

        self.hidden0 = nn.Sequential(
            nn.Conv2d(in_channels=2, out_channels=self.ndf, kernel_size=4, stride=2, padding=1, bias=False),
            nn.LeakyReLU(0.2),
        )
        self.hidden1 = nn.Sequential(
            nn.Conv2d(in_channels=self.ndf, out_channels=self.ndf * 2, kernel_size=4, stride=2, padding=1, bias=False),
            nn.BatchNorm2d(self.ndf * 2),
            nn.LeakyReLU(0.2),
            nn.Dropout(self.droupout_value)
        )
        self.hidden2 = nn.Sequential(
            nn.Conv2d(in_channels=self.ndf * 2, out_channels=self.ndf * 4, kernel_size=4, stride=2, padding=1, bias=False),
            #nn.BatchNorm2d(self.ndf * 4),
            nn.LeakyReLU(0.2),
            nn.Dropout(self.droupout_value)
        )
        self.hidden3 = nn.Sequential(
            nn.Conv2d(in_channels=self.ndf * 4, out_channels=self.ndf * 8, kernel_size=4, stride=2, padding=1, bias=False),
            nn.BatchNorm2d(self.ndf * 8),
            nn.LeakyReLU(0.2),
            nn.Dropout(self.droupout_value)
        )
        self.out = nn.Sequential(
            nn.Conv2d(in_channels=self.ndf * 8, out_channels=1, kernel_size=4, stride=1, padding=0, bias=False),
            torch.nn.Sigmoid()
        )

    def forward(self, x, y):
        y = self.condi(y.view(-1, 10))
        y = y.view(-1, 1, 64, 64)

        x = torch.cat((x, y), dim=1)

        x = self.hidden0(x)
        x = self.hidden1(x)
        x = self.hidden2(x)
        x = self.hidden3(x)
        x = self.out(x)

        return x


class Generator(torch.nn.Module):
    def __init__(self, n_features=100, ngf=16, c_channels=1, dropout_value=0.5):  # ngf feature map of generator
        super().__init__()
        self.ngf = ngf
        self.n_features = n_features
        self.c_channels = c_channels
        self.droupout_value = dropout_value

        self.hidden0 = nn.Sequential(
            nn.ConvTranspose2d(in_channels=self.n_features + 10, out_channels=self.ngf * 8,
                               kernel_size=4, stride=1, padding=0, bias=False),
            nn.BatchNorm2d(self.ngf * 8),
            nn.LeakyReLU(0.2)
        )

        self.hidden1 = nn.Sequential(
            nn.ConvTranspose2d(in_channels=self.ngf * 8, out_channels=self.ngf * 4,
                               kernel_size=4, stride=2, padding=1, bias=False),
            #nn.BatchNorm2d(self.ngf * 4),
            nn.LeakyReLU(0.2),
            nn.Dropout(self.droupout_value)
        )

        self.hidden2 = nn.Sequential(
            nn.ConvTranspose2d(in_channels=self.ngf * 4, out_channels=self.ngf * 2,
                               kernel_size=4, stride=2, padding=1, bias=False),
            nn.BatchNorm2d(self.ngf * 2),
            nn.LeakyReLU(0.2),
            nn.Dropout(self.droupout_value)
        )

        self.hidden3 = nn.Sequential(
            nn.ConvTranspose2d(in_channels=self.ngf * 2, out_channels=self.ngf,
                               kernel_size=4, stride=2, padding=1, bias=False),
            nn.BatchNorm2d(self.ngf),
            nn.LeakyReLU(0.2),
            nn.Dropout(self.droupout_value)
        )

        self.out = nn.Sequential(
            # "out_channels=1" because gray scale
            nn.ConvTranspose2d(in_channels=self.ngf, out_channels=1, kernel_size=4,
                               stride=2, padding=1, bias=False),
            nn.Tanh()
        )

    def forward(self, x, y):
        x_cond = torch.cat((x, y), dim=1)  # Combine flatten image with conditional input (class labels)

        x = self.hidden0(x_cond)           # Image goes into a "ConvTranspose2d" layer
        x = self.hidden1(x)
        x = self.hidden2(x)
        x = self.hidden3(x)
        x = self.out(x)

        return x


class Logger:
    def __init__(self, model_name, model1, model2, m1_optimizer, m2_optimizer, model_parameter, train_loader):
        self.out_dir = "data"
        self.model_name = model_name
        self.train_loader = train_loader
        self.model1 = model1
        self.model2 = model2
        self.model_parameter = model_parameter
        self.m1_optimizer = m1_optimizer
        self.m2_optimizer = m2_optimizer

        # Exclude Epochs of the model name. This make sense e.g. when we stop a training progress and continue later on.
        self.experiment_name = '_'.join("{!s}={!r}".format(k, v) for (k, v) in model_parameter.items())\
            .replace("Epochs" + "=" + str(model_parameter["Epochs"]), "")

        self.d_error = 0
        self.g_error = 0

        self.tb = SummaryWriter(log_dir=str(self.out_dir + "/log/" + self.model_name + "/runs/" + self.experiment_name))

        self.path_image = os.path.join(os.getcwd(), f'{self.out_dir}/log/{self.model_name}/images/{self.experiment_name}')
        self.path_model = os.path.join(os.getcwd(), f'{self.out_dir}/log/{self.model_name}/model/{self.experiment_name}')

        try:
            os.makedirs(self.path_image)
        except Exception as e:
            print("WARNING: ", str(e))

        try:
            os.makedirs(self.path_model)
        except Exception as e:
            print("WARNING: ", str(e))

    def log_graph(self, model1_input, model2_input, model1_label, model2_label):
        self.tb.add_graph(self.model1, input_to_model=(model1_input, model1_label))
        self.tb.add_graph(self.model2, input_to_model=(model2_input, model2_label))

    def log(self, num_epoch, d_error, g_error):
        self.d_error = d_error
        self.g_error = g_error

        self.tb.add_scalar("Discriminator Train Error", self.d_error, num_epoch)
        self.tb.add_scalar("Generator Train Error", self.g_error, num_epoch)

    def log_image(self, images, epoch, batch_num):
        grid = torchvision.utils.make_grid(images)
        torchvision.utils.save_image(grid, f'{self.path_image}\\Epoch_{epoch}_batch_{batch_num}.png')

        self.tb.add_image("Generator Image", grid)

    def log_histogramm(self):
        for name, param in self.model2.named_parameters():
            self.tb.add_histogram(name, param, self.model_parameter["Epochs"])
            self.tb.add_histogram(f'gen_{name}.grad', param.grad, self.model_parameter["Epochs"])

        for name, param in self.model1.named_parameters():
            self.tb.add_histogram(name, param, self.model_parameter["Epochs"])
            self.tb.add_histogram(f'dis_{name}.grad', param.grad, self.model_parameter["Epochs"])

    def log_model(self, num_epoch):
        torch.save({
            "epoch": num_epoch,
            "model_generator_state_dict": self.model1.state_dict(),
            "model_discriminator_state_dict": self.model2.state_dict(),
            "optimizer_generator_state_dict":  self.m1_optimizer.state_dict(),
            "optimizer_discriminator_state_dict":  self.m2_optimizer.state_dict(),
        }, str(self.path_model + f'\\{time.time()}_epoch{num_epoch}.pth'))

    def close(self, logger, images, num_epoch,  d_error, g_error):
        logger.log_model(num_epoch)
        logger.log_histogramm()
        logger.log(num_epoch, d_error, g_error)
        self.tb.close()

    def display_stats(self, epoch, batch_num, dis_error, gen_error):
        print(f'Epoch: [{epoch}/{self.model_parameter["Epochs"]}] '
              f'Batch: [{batch_num}/{len(self.train_loader)}] '
              f'Loss_D: {dis_error.data.cpu()}, '
              f'Loss_G: {gen_error.data.cpu()}')


def get_MNIST_dataset(num_workers_loader, model_parameter, out_dir="data"):
    compose = transforms.Compose([
        transforms.Resize((64, 64)),
        transforms.CenterCrop((64, 64)),
        transforms.ToTensor(),
        torchvision.transforms.Normalize(mean=[0.5], std=[0.5])
    ])

    dataset = datasets.MNIST(
        root=out_dir,
        train=True,
        download=True,
        transform=compose
    )

    train_loader = torch.utils.data.DataLoader(dataset,
                                               batch_size=model_parameter["batch_size"],
                                               num_workers=num_workers_loader,
                                               shuffle=model_parameter["shuffle"])

    return dataset, train_loader


def train_discriminator(p_optimizer, p_noise, p_images, p_fake_target, p_real_target, p_images_labels, p_fake_labels, device):
    p_optimizer.zero_grad()

    # 1.1 Train on real data
    pred_dis_real = discriminator(p_images, p_images_labels)
    error_real = loss(pred_dis_real, p_real_target)

    error_real.backward()

    # 1.2 Train on fake data
    fake_data = generator(p_noise, p_fake_labels).detach()
    fake_data = add_noise_to_image(fake_data, device)
    pred_dis_fake = discriminator(fake_data, p_fake_labels)
    error_fake = loss(pred_dis_fake, p_fake_target)

    error_fake.backward()

    p_optimizer.step()

    return error_fake + error_real


def train_generator(p_optimizer, p_noise, p_real_target, p_fake_labels, device):
    p_optimizer.zero_grad()

    fake_images = generator(p_noise, p_fake_labels)
    fake_images = add_noise_to_image(fake_images, device)
    pred_dis_fake = discriminator(fake_images, p_fake_labels)
    error_fake = loss(pred_dis_fake, p_real_target)  # because
    """
    We use "p_real_target" instead of "p_fake_target" because we want to 
    maximize that the discriminator is wrong.
    """

    error_fake.backward()

    p_optimizer.step()

    return fake_images, pred_dis_fake, error_fake


# TODO change to a Truncated normal distribution
def get_noise(batch_size, n_features=100):
    return torch.FloatTensor(batch_size, n_features, 1, 1).uniform_(-1, 1)


# We flip label of real and fate data. Better gradient flow I have told
def get_real_data_target(batch_size):
    return torch.FloatTensor(batch_size, 1, 1, 1).uniform_(0.0, 0.2)


def get_fake_data_target(batch_size):
    return torch.FloatTensor(batch_size, 1, 1, 1).uniform_(0.8, 1.1)


def image_to_vector(images):
    return torch.flatten(images, start_dim=1, end_dim=-1)


def vector_to_image(images):
    return images.view(images.size(0), 1, 28, 28)


def get_rand_labels(batch_size):
    return torch.randint(low=0, high=9, size=(batch_size,))


def load_model(model_load_path):
    if model_load_path:
        checkpoint = torch.load(model_load_path)

        discriminator.load_state_dict(checkpoint["model_discriminator_state_dict"])
        generator.load_state_dict(checkpoint["model_generator_state_dict"])

        dis_opti.load_state_dict(checkpoint["optimizer_discriminator_state_dict"])
        gen_opti.load_state_dict(checkpoint["optimizer_generator_state_dict"])

        return checkpoint["epoch"]

    else:
        return 0


def init_model_optimizer(model_parameter, device):
    # Initialize the Models
    discriminator = Discriminator(ndf=model_parameter["ndf"], dropout_value=model_parameter["dropout"]).to(device)
    generator = Generator(ngf=model_parameter["ngf"], dropout_value=model_parameter["dropout"]).to(device)

    # train
    dis_opti = optim.Adam(discriminator.parameters(), lr=model_parameter["learning_rate_dis"], betas=(0.5, 0.999))
    gen_opti = optim.Adam(generator.parameters(), lr=model_parameter["learning_rate_gen"], betas=(0.5, 0.999))

    return discriminator, generator, dis_opti, gen_opti


def get_hot_vector_encode(labels, device):
    return torch.eye(10)[labels].view(-1, 10, 1, 1).to(device)


def add_noise_to_image(images, device, level_of_noise=0.1):
    return images[0].to(device) + (level_of_noise) * torch.randn(images.shape).to(device)


if __name__ == "__main__":
    # Hyperparameter
    model_parameter = {
        "batch_size": 500,
        "learning_rate_dis": 0.0002,
        "learning_rate_gen": 0.0002,
        "shuffle": False,
        "Epochs": 10,
        "ndf": 64,
        "ngf": 64,
        "dropout": 0.5
    }

    # Parameter
    r_frequent = 10        # How many samples we save for replay per batch (batch_size / r_frequent).
    model_name = "CDCGAN"   # The name of you model e.g. "Gan"
    num_workers_loader = 1  # How many workers should load the data
    sample_save_size = 16   # How many numbers your saved imaged should show
    device = "cuda"         # Which device should be used to train the neural network
    model_load_path = ""    # If set load model instead of training from new
    num_epoch_log = 1       # How frequent you want to log/
    torch.manual_seed(43)   # Sets a seed for torch for reproducibility

    dataset_train, train_loader = get_MNIST_dataset(num_workers_loader, model_parameter)  # Get dataset

    # Initialize the Models and optimizer
    discriminator, generator, dis_opti, gen_opti = init_model_optimizer(model_parameter, device)  # Init model/Optimizer

    start_epoch = load_model(model_load_path)  # when we want to load a model

    # Init Logger
    logger = Logger(model_name, generator, discriminator, gen_opti, dis_opti, model_parameter, train_loader)

    loss = nn.BCELoss()

    images, labels = next(iter(train_loader))  # For logging

    # For testing
    # pred = generator(get_noise(model_parameter["batch_size"]).to(device), get_hot_vector_encode(get_rand_labels(model_parameter["batch_size"]), device))
    # dis = discriminator(images.to(device), get_hot_vector_encode(labels, device))

    logger.log_graph(get_noise(model_parameter["batch_size"]).to(device), images.to(device),
                     get_hot_vector_encode(get_rand_labels(model_parameter["batch_size"]), device),
                     get_hot_vector_encode(labels, device))


    # Array to store
    exp_replay = torch.tensor([]).to(device)

    for num_epoch in range(start_epoch, model_parameter["Epochs"]):
        for batch_num, data_loader in enumerate(train_loader):
            images, labels = data_loader
            images = add_noise_to_image(images, device)  # Add noise to the images

            # 1. Train Discriminator
            dis_error = train_discriminator(
                                            dis_opti,
                                            get_noise(model_parameter["batch_size"]).to(device),
                                            images.to(device),
                                            get_fake_data_target(model_parameter["batch_size"]).to(device),
                                            get_real_data_target(model_parameter["batch_size"]).to(device),
                                            get_hot_vector_encode(labels, device),
                                            get_hot_vector_encode(
                                                get_rand_labels(model_parameter["batch_size"]), device),
                                            device
                                            )

            # 2. Train Generator
            fake_image, pred_dis_fake, gen_error = train_generator(
                                                                  gen_opti,
                                                                  get_noise(model_parameter["batch_size"]).to(device),
                                                                  get_real_data_target(model_parameter["batch_size"]).to(device),
                                                                  get_hot_vector_encode(
                                                                      get_rand_labels(model_parameter["batch_size"]),
                                                                      device),
                                                                  device
                                                                  )


            # Store a random point for experience replay
            perm = torch.randperm(fake_image.size(0))
            r_idx = perm[:max(1, int(model_parameter["batch_size"] / r_frequent))]
            r_samples = add_noise_to_image(fake_image[r_idx], device)
            exp_replay = torch.cat((exp_replay, r_samples), 0).detach()

            if exp_replay.size(0) >= model_parameter["batch_size"]:
                # Train on experienced data
                dis_opti.zero_grad()

                r_label = get_hot_vector_encode(torch.zeros(exp_replay.size(0)).numpy(), device)
                pred_dis_real = discriminator(exp_replay, r_label)
                error_real = loss(pred_dis_real,  get_fake_data_target(exp_replay.size(0)).to(device))

                error_real.backward()

                dis_opti.step()

                print(f'Epoch: [{num_epoch}/{model_parameter["Epochs"]}] '
                      f'Batch: Replay/Experience batch '
                      f'Loss_D: {error_real.data.cpu()}, '
                      )

                exp_replay = torch.tensor([]).to(device)

            logger.display_stats(epoch=num_epoch, batch_num=batch_num, dis_error=dis_error, gen_error=gen_error)

            if batch_num % 100 == 0:
                logger.log_image(fake_image[:sample_save_size], num_epoch, batch_num)

        logger.log(num_epoch, dis_error, gen_error)
        if num_epoch % num_epoch_log == 0:
            logger.log_model(num_epoch)
            logger.log_histogramm()
    logger.close(logger, fake_image[:sample_save_size], num_epoch, dis_error, gen_error)

First link to my Code (Pastebin)
Second link to my Code (0bin)

Conclusion:

Since I implemented all these things (e.g. label smoothing) which are considered beneficial to a GAN/DCGAN.
And my Model still performs worse than the Tutorial DCGAN from PyTorch I think I might have a bug in my code but I can't seem to find it.

Reproducibility:

You should be able to just copy the code and run it if you have the libraries that I imported installed to look for yourself if you can find anything.

I appreciate any feedback.


Solution 1:

So I solved this issue a while ago, but forgot to post an answer on stack overflow. So I will simply post my code here which should work probably pretty good. Some disclaimer:

  • I am not quite sure if it works since I did this a year ago
  • its for 128x128px Images MNIST
  • It's not a vanilla GAN I used various optimization techniques
  • If you want to use it you need to change various details, such as the training dataset

Resources:

  • Multi-Scale Gradients
  • Instance Noise
  • Various tricks I used
  • More tricks

``

import torch
from torch.autograd import Variable
import torch.nn as nn
import torch.nn.functional as F
import torchvision
import torchvision.transforms as transforms
from torch.utils.data import DataLoader

import pytorch_lightning as pl
from pytorch_lightning import loggers

from numpy.random import choice

import os
from pathlib import Path
import shutil

from collections import OrderedDict

# custom weights initialization called on netG and netD
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)

# randomly flip some labels
def noisy_labels(y, p_flip=0.05):  # # flip labels with 5% probability
    # determine the number of labels to flip
    n_select = int(p_flip * y.shape[0])
    # choose labels to flip
    flip_ix = choice([i for i in range(y.shape[0])], size=n_select)
    # invert the labels in place
    y[flip_ix] = 1 - y[flip_ix]
    return y

class AddGaussianNoise(object):
    def __init__(self, mean=0.0, std=0.1):
        self.std = std
        self.mean = mean

    def __call__(self, tensor):
        tensor = tensor.cuda()
        return tensor + (torch.randn(tensor.size()) * self.std + self.mean).cuda()

    def __repr__(self):
        return self.__class__.__name__ + '(mean={0}, std={1})'.format(self.mean, self.std)

def resize2d(img, size):
    return (F.adaptive_avg_pool2d(img, size).data).cuda()

def get_valid_labels(img):
    return ((0.8 - 1.1) * torch.rand(img.shape[0], 1, 1, 1) + 1.1).cuda()  # soft labels

def get_unvalid_labels(img):
    return (noisy_labels((0.0 - 0.3) * torch.rand(img.shape[0], 1, 1, 1) + 0.3)).cuda()  # soft labels

class Generator(pl.LightningModule):
    def __init__(self, ngf, nc, latent_dim):
        super(Generator, self).__init__()
        self.ngf = ngf
        self.latent_dim = latent_dim
        self.nc = nc

        self.fc0 = nn.Sequential(
            # input is Z, going into a convolution
            nn.utils.spectral_norm(nn.ConvTranspose2d(latent_dim, ngf * 16, 4, 1, 0, bias=False)),
            nn.LeakyReLU(0.2, inplace=True),
            nn.BatchNorm2d(ngf * 16)
        )

        self.fc1 = nn.Sequential(
            # state size. (ngf*8) x 4 x 4
            nn.utils.spectral_norm(nn.ConvTranspose2d(ngf * 16, ngf * 8, 4, 2, 1, bias=False)),
            nn.LeakyReLU(0.2, inplace=True),
            nn.BatchNorm2d(ngf * 8)
        )

        self.fc2 = nn.Sequential(
            # state size. (ngf*4) x 8 x 8
            nn.utils.spectral_norm(nn.ConvTranspose2d(ngf * 8, ngf * 4, 4, 2, 1, bias=False)),
            nn.LeakyReLU(0.2, inplace=True),
            nn.BatchNorm2d(ngf * 4)
        )

        self.fc3 = nn.Sequential(
            # state size. (ngf*2) x 16 x 16
            nn.utils.spectral_norm(nn.ConvTranspose2d(ngf * 4, ngf * 2, 4, 2, 1, bias=False)),
            nn.LeakyReLU(0.2, inplace=True),
            nn.BatchNorm2d(ngf * 2)
        )

        self.fc4 = nn.Sequential(
            # state size. (ngf) x 32 x 32
            nn.utils.spectral_norm(nn.ConvTranspose2d(ngf * 2, ngf, 4, 2, 1, bias=False)),
            nn.LeakyReLU(0.2, inplace=True),
            nn.BatchNorm2d(ngf)
        )

        self.fc5 = nn.Sequential(
            # state size. (nc) x 64 x 64
            nn.utils.spectral_norm(nn.ConvTranspose2d(ngf, nc, 4, 2, 1, bias=False)),
            nn.Tanh()
        )

        # state size. (nc) x 128 x 128

        # For Multi-Scale Gradient
        # Converting the intermediate layers into images
        self.fc0_r = nn.Conv2d(ngf * 16, self.nc, 1)
        self.fc1_r = nn.Conv2d(ngf * 8, self.nc, 1)
        self.fc2_r = nn.Conv2d(ngf * 4, self.nc, 1)
        self.fc3_r = nn.Conv2d(ngf * 2, self.nc, 1)
        self.fc4_r = nn.Conv2d(ngf, self.nc, 1)

    def forward(self, input):
        x_0 = self.fc0(input)
        x_1 = self.fc1(x_0)
        x_2 = self.fc2(x_1)
        x_3 = self.fc3(x_2)
        x_4 = self.fc4(x_3)
        x_5 = self.fc5(x_4)

        # For Multi-Scale Gradient
        # Converting the intermediate layers into images
        x_0_r = self.fc0_r(x_0)
        x_1_r = self.fc1_r(x_1)
        x_2_r = self.fc2_r(x_2)
        x_3_r = self.fc3_r(x_3)
        x_4_r = self.fc4_r(x_4)

        return x_5, x_0_r, x_1_r, x_2_r, x_3_r, x_4_r

class Discriminator(pl.LightningModule):
    def __init__(self, ndf, nc):
        super(Discriminator, self).__init__()
        self.nc = nc
        self.ndf = ndf

        self.fc0 = nn.Sequential(
            # input is (nc) x 128 x 128
            nn.utils.spectral_norm(nn.Conv2d(nc, ndf, 4, 2, 1, bias=False)),
            nn.LeakyReLU(0.2, inplace=True)
        )

        self.fc1 = nn.Sequential(
            # state size. (ndf) x 64 x 64
            nn.utils.spectral_norm(nn.Conv2d(ndf + nc, ndf * 2, 4, 2, 1, bias=False)),
            # "+ nc" because of multi scale gradient
            nn.LeakyReLU(0.2, inplace=True),
            nn.BatchNorm2d(ndf * 2)
        )

        self.fc2 = nn.Sequential(
            # state size. (ndf*2) x 32 x 32
            nn.utils.spectral_norm(nn.Conv2d(ndf * 2 + nc, ndf * 4, 4, 2, 1, bias=False)),
            # "+ nc" because of multi scale gradient
            nn.LeakyReLU(0.2, inplace=True),
            nn.BatchNorm2d(ndf * 4)
        )

        self.fc3 = nn.Sequential(
            # state size. (ndf*4) x 16 x 16e
            nn.utils.spectral_norm(nn.Conv2d(ndf * 4 + nc, ndf * 8, 4, 2, 1, bias=False)),
            # "+ nc" because of multi scale gradient
            nn.LeakyReLU(0.2, inplace=True),
            nn.BatchNorm2d(ndf * 8),
        )

        self.fc4 = nn.Sequential(
            # state size. (ndf*8) x 8 x 8
            nn.utils.spectral_norm(nn.Conv2d(ndf * 8 + nc, ndf * 16, 4, 2, 1, bias=False)),
            nn.LeakyReLU(0.2, inplace=True),
            nn.BatchNorm2d(ndf * 16)
        )

        self.fc5 = nn.Sequential(
            # state size. (ndf*8) x 4 x 4
            nn.utils.spectral_norm(nn.Conv2d(ndf * 16 + nc, 1, 4, 1, 0, bias=False)),
            nn.Sigmoid()
        )

        # state size. 1 x 1 x 1

    def forward(self, input, detach_or_not):
        # When we train i ncombination with generator we use multi scale gradient.
        x, x_0_r, x_1_r, x_2_r, x_3_r, x_4_r = input
        if detach_or_not:
            x = x.detach()

        x_0 = self.fc0(x)

        x_0 = torch.cat((x_0, x_4_r), dim=1)  # Concat Multi-Scale Gradient
        x_1 = self.fc1(x_0)

        x_1 = torch.cat((x_1, x_3_r), dim=1)  # Concat Multi-Scale Gradient
        x_2 = self.fc2(x_1)

        x_2 = torch.cat((x_2, x_2_r), dim=1)  # Concat Multi-Scale Gradient
        x_3 = self.fc3(x_2)

        x_3 = torch.cat((x_3, x_1_r), dim=1)  # Concat Multi-Scale Gradient
        x_4 = self.fc4(x_3)

        x_4 = torch.cat((x_4, x_0_r), dim=1)  # Concat Multi-Scale Gradient
        x_5 = self.fc5(x_4)

        return x_5

class DCGAN(pl.LightningModule):

    def __init__(self, hparams, checkpoint_folder, experiment_name):
        super().__init__()
        self.hparams = hparams
        self.checkpoint_folder = checkpoint_folder
        self.experiment_name = experiment_name

        # networks
        self.generator = Generator(ngf=hparams.ngf, nc=hparams.nc, latent_dim=hparams.latent_dim)
        self.discriminator = Discriminator(ndf=hparams.ndf, nc=hparams.nc)
        self.generator.apply(weights_init)
        self.discriminator.apply(weights_init)

        # cache for generated images
        self.generated_imgs = None
        self.last_imgs = None

        # For experience replay
        self.exp_replay_dis = torch.tensor([])


    def forward(self, z):
        return self.generator(z)

    def adversarial_loss(self, y_hat, y):
        return F.binary_cross_entropy(y_hat, y)

    def training_step(self, batch, batch_nb, optimizer_idx):
        # For adding Instance noise for more visit: https://www.inference.vc/instance-noise-a-trick-for-stabilising-gan-training/
        std_gaussian = max(0, self.hparams.level_of_noise - (
                (self.hparams.level_of_noise * 2) * (self.current_epoch / self.hparams.epochs)))
        AddGaussianNoiseInst = AddGaussianNoise(std=std_gaussian)  # the noise decays over time

        imgs, _ = batch
        imgs = AddGaussianNoiseInst(imgs)  # Adding instance noise to real images
        self.last_imgs = imgs

        # train generator
        if optimizer_idx == 0:
            # sample noise
            z = torch.randn(imgs.shape[0], self.hparams.latent_dim, 1, 1).cuda()

            # generate images
            self.generated_imgs = self(z)

            # ground truth result (ie: all fake)
            g_loss = self.adversarial_loss(self.discriminator(self.generated_imgs, False), get_valid_labels(self.generated_imgs[0]))  # adversarial loss is binary cross-entropy; [0] is the image of the last layer

            tqdm_dict = {'g_loss': g_loss}
            log = {'g_loss': g_loss, "std_gaussian": std_gaussian}
            output = OrderedDict({
                'loss': g_loss,
                'progress_bar': tqdm_dict,
                'log': log
            })
            return output

        # train discriminator
        if optimizer_idx == 1:
            # Measure discriminator's ability to classify real from generated samples
            # how well can it label as real?
            real_loss = self.adversarial_loss(
                self.discriminator([imgs, resize2d(imgs, 4), resize2d(imgs, 8), resize2d(imgs, 16), resize2d(imgs, 32), resize2d(imgs, 64)],
                                   False), get_valid_labels(imgs))

            fake_loss = self.adversarial_loss(self.discriminator(self.generated_imgs, True), get_unvalid_labels(
                self.generated_imgs[0]))  # how well can it label as fake?; [0] is the image of the last layer

            # discriminator loss is the average of these
            d_loss = (real_loss + fake_loss) / 2

            tqdm_dict = {'d_loss': d_loss}
            log = {'d_loss': d_loss, "std_gaussian": std_gaussian}
            output = OrderedDict({
                'loss': d_loss,
                'progress_bar': tqdm_dict,
                'log': log
            })
            return output

    def configure_optimizers(self):
        lr_gen = self.hparams.lr_gen
        lr_dis = self.hparams.lr_dis
        b1 = self.hparams.b1
        b2 = self.hparams.b2

        opt_g = torch.optim.Adam(self.generator.parameters(), lr=lr_gen, betas=(b1, b2))
        opt_d = torch.optim.Adam(self.discriminator.parameters(), lr=lr_dis, betas=(b1, b2))
        return [opt_g, opt_d], []

    def backward(self, trainer, loss, optimizer, optimizer_idx: int) -> None:
        loss.backward(retain_graph=True)

    def train_dataloader(self):
        # transform = transforms.Compose([transforms.Resize((self.hparams.image_size, self.hparams.image_size)),
        #                                 transforms.ToTensor(),
        #                                 transforms.Normalize([0.5], [0.5])])
        # dataset = torchvision.datasets.MNIST(os.getcwd(), train=False, download=True, transform=transform)
        # return DataLoader(dataset, batch_size=self.hparams.batch_size)
        # transform = transforms.Compose([transforms.Resize((self.hparams.image_size, self.hparams.image_size)),
        #                                 transforms.ToTensor(),
        #                                 transforms.Normalize([0.5], [0.5])
        #                                 ])

        # train_dataset = torchvision.datasets.ImageFolder(
        #     root="./drive/My Drive/datasets/flower_dataset/",
        #     # root="./drive/My Drive/datasets/ghibli_dataset_small_overfit/",
        #     transform=transform
        # )
        # return DataLoader(train_dataset, num_workers=self.hparams.num_workers, shuffle=True,
        #                   batch_size=self.hparams.batch_size)

        transform = transforms.Compose([transforms.Resize((self.hparams.image_size, self.hparams.image_size)),
                                        transforms.ToTensor(),
                                        transforms.Normalize([0.5], [0.5])
                                        ])
        train_dataset = torchvision.datasets.ImageFolder(
            root="ghibli_dataset_small_overfit/",
            transform=transform
        )
        return DataLoader(train_dataset, num_workers=self.hparams.num_workers, shuffle=True,
                          batch_size=self.hparams.batch_size)

    def on_epoch_end(self):
        z = torch.randn(4, self.hparams.latent_dim, 1, 1).cuda()
        # match gpu device (or keep as cpu)
        if self.on_gpu:
            z = z.cuda(self.last_imgs.device.index)

        # log sampled images
        sample_imgs = self.generator(z)[0]
        torchvision.utils.save_image(sample_imgs, f'generated_images_epoch{self.current_epoch}.png')

        # save model
        if self.current_epoch % self.hparams.save_model_every_epoch == 0:
            trainer.save_checkpoint(
                self.checkpoint_folder + "/" + self.experiment_name + "_epoch_" + str(self.current_epoch) + ".ckpt")

from argparse import Namespace

args = {
    'batch_size': 128, # batch size
    'lr_gen': 0.0003,  # TTUR;learnin rate of both networks; tested value: 0.0002
    'lr_dis': 0.0003,  # TTUR;learnin rate of both networks; tested value: 0.0002
    'b1': 0.5,  # Momentum for adam; tested value(dcgan paper): 0.5
    'b2': 0.999,  # Momentum for adam; tested value(dcgan paper): 0.999
    'latent_dim': 256,  # tested value which worked(in V4_1): 100
    'nc': 3,  # number of color channels
    'ndf': 8,  # number of discriminator features
    'ngf': 8,  # number of generator features
    'epochs': 4,  # the maxima lamount of epochs the algorith should run
    'save_model_every_epoch': 1,  # how often we save our model
    'image_size': 128, # size of the image
    'num_workers': 3,
    'level_of_noise': 0.1,  # how much instance noise we introduce(std; tested value: 0.15 and 0.1
    'experience_save_per_batch': 1,  # this value should be very low; tested value which works: 1
    'experience_batch_size': 50  # this value shouldnt be too high; tested value which works: 50
}
hparams = Namespace(**args)

# Parameters
experiment_name = "DCGAN_6_2_MNIST_128px"
dataset_name = "mnist"
checkpoint_folder = "DCGAN/"
tags = ["DCGAN", "128x128"]
dirpath = Path(checkpoint_folder)

# defining net
net = DCGAN(hparams, checkpoint_folder, experiment_name)

torch.autograd.set_detect_anomaly(True)
trainer = pl.Trainer( # resume_from_checkpoint="DCGAN_V4_2_GHIBLI_epoch_999.ckpt",
    max_epochs=args["epochs"],
    gpus=1
)

trainer.fit(net)

``