File size: 8,307 Bytes
e61c431
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
import torch
import lightning as L
import torch.optim as optim

from models.generator import Generator
from models.discriminator import Discriminator
from utility.helper import initialize_weights, plot_images_from_tensor
from utility.wgan_gp import gradient_penalty, calculate_generator_loss, calculate_critic_loss



class ConditionalWGAN_GP(L.LightningModule):
    def __init__(self, image_channel, label_channel, image_size, learning_rate, z_dim, embed_size, num_classes, critic_repeats, feature_gen, feature_critic, c_lambda, beta_1, beta_2, display_step):
        super().__init__()
        
        self.automatic_optimization = False
        
        self.image_size = image_size
        self.critic_repeats = critic_repeats
        self.c_lambda = c_lambda
        
        self.generator = Generator(
            embed_size=embed_size,
            num_classes=num_classes,
            image_size=image_size,
            features_generator=feature_gen,
            input_dim=z_dim,
        )
        
        self.critic = Discriminator(
            num_classes=num_classes,
            embed_size=embed_size,
            image_size=image_size,
            features_discriminator=feature_critic,
            image_channel=image_channel,
            label_channel=label_channel,
        )
        
        
        self.critic_losses = []
        self.generator_losses = []
        self.curr_step = 0
        
        self.fixed_latent_space = torch.randn(25, z_dim, 1, 1)
        self.fixed_label = torch.tensor([i % num_classes for i in range(25)])
        
        self.save_hyperparameters()
    
    def configure_optimizers(self):
        # READ: https://lightning.ai/docs/pytorch/stable/common/optimization.html#use-multiple-optimizers-like-gans
        # READ: https://lightning.ai/docs/pytorch/stable/model/manual_optimization.html
        # READ: https://lightning.ai/docs/pytorch/stable/model/build_model_advanced.html
        # READ: https://lightning.ai/docs/pytorch/stable/api/lightning.pytorch.core.LightningModule.html#lightning.pytorch.core.LightningModule.backward
        # READ: https://lightning.ai/docs/pytorch/stable/common/lightning_module.html#manual-backward
        optimizer_G = optim.Adam(self.generator.parameters(), lr=self.hparams.learning_rate, betas=(self.hparams.beta_1, self.hparams.beta_2))
        optimizer_C = optim.Adam(self.critic.parameters(), lr=self.hparams.learning_rate, betas=(self.hparams.beta_1, self.hparams.beta_2))

        return optimizer_G, optimizer_C
    
    def on_load_checkpoint(self, checkpoint):
        # List of keys that you expect to load from the checkpoint
        keys_to_load = ['critic_losses', 'generator_losses', 'curr_step', 'fixed_latent_space', 'fixed_label']

        # Iterate over the keys and load them if they exist in the checkpoint
        for key in keys_to_load:
            if key in checkpoint:
                setattr(self, key, checkpoint[key])
    
    def on_save_checkpoint(self, checkpoint):
        # Save necessary variable to checkpoint
        checkpoint['critic_losses'] = self.critic_losses
        checkpoint['generator_losses'] = self.generator_losses
        checkpoint['curr_step'] = self.curr_step
        checkpoint['fixed_latent_space'] = self.fixed_latent_space
        checkpoint['fixed_label'] = self.fixed_label
    
    def on_train_start(self):
        if self.current_epoch == 0:
            self.generator.apply(initialize_weights)
            self.critic.apply(initialize_weights)
    
    def training_step(self, batch, batch_idx):
        # Get the Optimizers
        opt_generator, opt_critic = self.optimizers()
        
        # Get Data and Label
        X, labels = batch
        
        # Get the current batch size
        batch_size = X.shape[0]
        
        ##############################
        # Train Critic ###############
        ##############################
        mean_critic_loss_for_this_iteration = 0
        
        for _ in range(self.critic_repeats):
            # Clean the Gradient
            opt_critic.zero_grad()
            
            # Generate the noise.
            noise = torch.randn(batch_size, self.hparams.z_dim, device=self.device)
            
            # Generate fake image.
            fake = self.generator(noise, labels)
            
            # Get the Critic's prediction on the reals and fakes
            critic_fake_pred = self.critic(fake.detach(), labels)
            critic_real_pred = self.critic(X, labels)
            
            # Calculate the Critic loss using WGAN
            
            # Generate epsilon for interpolate image.
            epsilon = torch.rand(batch_size, 1, 1, 1, device=self.device, requires_grad=True)
            
            # Calculate Gradient Penalty Critic model
            gp = gradient_penalty(self.critic, labels, X, fake.detach(), epsilon)
            
            # calculate full of WGAN-GP loss for Critic
            critic_loss = calculate_critic_loss(
                critic_fake_pred, critic_real_pred, gp, self.c_lambda
            )
            
            # Keep track of the average critic loss in this batch
            mean_critic_loss_for_this_iteration += critic_loss.item() / self.critic_repeats
            
            # Update the gradients Criticz
            # self.manual_backward(critic_loss, retain_graph=True)
            self.manual_backward(critic_loss) # no need retain graph cause, already detach() on the image, so it will cut from backpropagate. use that retain_graph=True if not using detach()
            
            # Update the optimizer
            opt_critic.step()            
        
        ##############################
        # Train Generator ############
        ##############################
        
        # Clean the gradient
        opt_generator.zero_grad()
        
        # Generate the noise.
        noise = torch.randn(batch_size, self.hparams.z_dim, device=self.device)
        
        # Generate fake image.
        fake = self.generator(noise, labels)
        
        # Get the Critic's prediction on the fakes by generator
        generator_fake_predictions = self.critic(fake, labels)
        
        # Calculate loss for Generator
        generator_loss = calculate_generator_loss(generator_fake_predictions)
        
        # update the gradient generator
        self.manual_backward(generator_loss)
        
        # Update the optimizer
        opt_generator.step()
        
        ##############################
        # Visualization ##############
        ##############################
        
        if self.curr_step % self.hparams.display_step == 0 and self.curr_step > 0:
            VISUALIZE = True
            if VISUALIZE:
                with torch.no_grad():
                    fake_images_fixed = self.generator(
                        self.fixed_latent_space.to(self.device),
                        self.fixed_label.to(self.device)
                    )
                    
            path_save = f"/kaggle/working/generates/generated-{self.curr_step}-step.png"
            plot_images_from_tensor(fake_images_fixed, size=(3, self.image_size, self.image_size), show=False, save_path=path_save)
            plot_images_from_tensor(X, size=(3, self.image_size, self.image_size), show=False)
            
            print(f" ==== Critic Loss: {mean_critic_loss_for_this_iteration} ==== ")
            print(f" ==== Generator Loss: {generator_loss.item()} ==== ")
         
        self.curr_step += 1
        
        ##############################
        # Logging ####################
        ##############################
        # Store the loss Critic into Log
        self.log("critic_loss", mean_critic_loss_for_this_iteration, on_step=False, on_epoch=True, prog_bar=True)
        self.log("generator_loss", generator_loss.item(), on_step=False, on_epoch=True, prog_bar=True)
        
        # store into list, so can used later for visualization
        self.critic_losses.append(mean_critic_loss_for_this_iteration)
        self.generator_losses.append(generator_loss.item())
    
    def forward(self, noise, labels):
        return self.generator(noise, labels)
    
    def predict_step(self, noise, labels):
        return self.generator(noise, labels)