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Generative Deep Learning Updated Edition

Chapter 10: Project: Image Generation with Diffusion Models

10.3 Training the Diffusion Model

Training the diffusion model is a crucial step in our image generation project. This process involves optimizing the model to predict and remove noise from the images, enabling it to transform random noise into coherent and structured images. In this section, we will cover the detailed process of training the diffusion model, including data preparation, training loop, and monitoring the training progress.

10.3.1 Preparing the Data

Before we start training, we need to ensure that our data is prepared and ready for the training process. This involves creating batches of noisy images and their corresponding denoised targets for the model to learn from.

Example: Data Preparation

from tensorflow.keras.preprocessing.image import ImageDataGenerator

# Define the data augmentation pipeline
datagen = ImageDataGenerator(
    rotation_range=20,
    width_shift_range=0.2,
    height_shift_range=0.2,
    horizontal_flip=True,
)

# Fit the data augmentation pipeline on the training data
datagen.fit(train_images)

# Example of creating a data generator
train_generator = datagen.flow(train_images, train_images, batch_size=32)
val_generator = datagen.flow(val_images, val_images, batch_size=32)

# Check the shape of a batch of training data
for batch_images, batch_labels in train_generator:
    print(f"Batch image shape: {batch_images.shape}")
    print(f"Batch label shape: {batch_labels.shape}")
    break

This code is using the TensorFlow Keras library to set up the ImageDataGenerator. This generator applies data augmentation techniques to image data, including rotation, width and height shifts, and horizontal flips. The generator is then fitted with training images. A training and validation generator is created from the training and validation image data with a batch size of 32. Finally, the code prints the shape of a batch of training data and labels to check the dimensions.

10.3.2 Defining the Training Loop

The training loop involves iterating over the dataset for a specified number of epochs, applying the forward diffusion process to add noise to the images, and then using the model to predict and remove this noise. During each iteration, the model's parameters are updated to minimize the loss, which is the difference between the predicted and actual noise.

Example: Training Loop

import numpy as np

# Define the number of training steps and epochs
num_steps = 10
epochs = 50

# Define a function to create step encodings
def create_step_encodings(num_samples, d_model):
    t = np.arange(num_samples).reshape(-1, 1)
    return sinusoidal_step_encoding(t, d_model)

# Training loop
for epoch in range(epochs):
    print(f"Epoch {epoch + 1}/{epochs}")
    for batch_images, _ in train_generator:
        # Apply forward diffusion to the batch images
        noisy_images = noise_layer(batch_images, training=True)

        # Create step encodings
        step_encodings = create_step_encodings(batch_images.shape[0], d_model)

        # Train the model
        loss = diffusion_model.train_on_batch([batch_images, step_encodings], batch_images)
        print(f"Loss: {loss}")

    # Validate the model on the validation set
    val_loss = 0
    for val_batch_images, _ in val_generator:
        noisy_val_images = noise_layer(val_batch_images, training=False)
        step_encodings = create_step_encodings(val_batch_images.shape[0], d_model)
        val_loss += diffusion_model.test_on_batch([val_batch_images, step_encodings], val_batch_images)
    val_loss /= len(val_generator)
    print(f"Validation Loss: {val_loss}")

This code outlines the training loop for the diffusion model. The model is trained for a specified number of epochs, with each epoch consisting of a number of steps.

In each epoch, the model is trained using the train_on_batch method on batches of images and their corresponding step encodings. The step encoding is a sinusoidal function of the timestep, and it is created using the create_step_encodings function.

The script also introduces noise to the images through the noise_layer function, and it calculates the loss of the model after each batch.

After each epoch, the model is validated on a validation set, and the average validation loss is calculated and printed.

10.3.3 Monitoring the Training Progress

To monitor the training progress, we can plot the training and validation loss over epochs. This helps us understand how well the model is learning and whether it is overfitting or underfitting the data.

Example: Monitoring Training Progress

import matplotlib.pyplot as plt

# Lists to store the training and validation loss
train_losses = []
val_losses = []

# Modified training loop to store the loss values
for epoch in range(epochs):
    print(f"Epoch {epoch + 1}/{epochs}")
    epoch_train_loss = 0
    for batch_images, _ in train_generator:
        noisy_images = noise_layer(batch_images, training=True)
        step_encodings = create_step_encodings(batch_images.shape[0], d_model)
        loss = diffusion_model.train_on_batch([batch_images, step_encodings], batch_images)
        epoch_train_loss += loss
    epoch_train_loss /= len(train_generator)
    train_losses.append(epoch_train_loss)

    val_loss = 0
    for val_batch_images, _ in val_generator:
        noisy_val_images = noise_layer(val_batch_images, training=False)
        step_encodings = create_step_encodings(val_batch_images.shape[0], d_model)
        val_loss += diffusion_model.test_on_batch([val_batch_images, step_encodings], val_batch_images)
    val_loss /= len(val_generator)
    val_losses.append(val_loss)

    print(f"Training Loss: {epoch_train_loss}")
    print(f"Validation Loss: {val_loss}")

# Plot the training and validation loss
plt.plot(train_losses, label='Training Loss')
plt.plot(val_losses, label='Validation Loss')
plt.xlabel('Epoch')
plt.ylabel('Loss')
plt.legend()
plt.title('Training and Validation Loss')
plt.show()

This code is used to train the diffusion model with a generator of training and validation data. The model is trained over a set number of epochs. For each epoch, the code introduces noise to the images, creates step encodings, and then trains the model on the noisy images. It computes the average training loss for each epoch and stores it in a list.

The same process is also done for the validation data, but instead of training, the model is tested on the validation data and the average validation loss for each epoch is recorded. Finally, it plots the training and validation losses over the epochs, allowing the user to visually assess the model's performance over time.

10.3.4 Saving the Trained Model

After training the model, it is important to save it for future use. This allows us to reuse the model without having to retrain it from scratch.

Example: Saving the Model

# Save the trained diffusion model
diffusion_model.save('diffusion_model.h5')

# Load the model later if needed
loaded_model = tf.keras.models.load_model('diffusion_model.h5')

The code is saving the trained diffusion model to a file named 'diffusion_model.h5' and then demonstrating how to load that saved model back into the program for later use.

Summary

In this section, we covered the detailed process of training the diffusion model for image generation. We started by preparing the data, including creating batches of noisy images and their corresponding denoised targets. We then defined the training loop, where we applied the forward diffusion process and used the model to predict and remove noise. We also emphasized the importance of monitoring the training progress by plotting the training and validation loss.

Finally, we discussed how to save the trained model for future use. By following these steps, you can effectively train a diffusion model to generate high-quality images from random noise. In the next sections, we will generate images using the trained model and evaluate its performance, providing a comprehensive understanding of how to apply diffusion models to real-world image generation tasks.

10.3 Training the Diffusion Model

Training the diffusion model is a crucial step in our image generation project. This process involves optimizing the model to predict and remove noise from the images, enabling it to transform random noise into coherent and structured images. In this section, we will cover the detailed process of training the diffusion model, including data preparation, training loop, and monitoring the training progress.

10.3.1 Preparing the Data

Before we start training, we need to ensure that our data is prepared and ready for the training process. This involves creating batches of noisy images and their corresponding denoised targets for the model to learn from.

Example: Data Preparation

from tensorflow.keras.preprocessing.image import ImageDataGenerator

# Define the data augmentation pipeline
datagen = ImageDataGenerator(
    rotation_range=20,
    width_shift_range=0.2,
    height_shift_range=0.2,
    horizontal_flip=True,
)

# Fit the data augmentation pipeline on the training data
datagen.fit(train_images)

# Example of creating a data generator
train_generator = datagen.flow(train_images, train_images, batch_size=32)
val_generator = datagen.flow(val_images, val_images, batch_size=32)

# Check the shape of a batch of training data
for batch_images, batch_labels in train_generator:
    print(f"Batch image shape: {batch_images.shape}")
    print(f"Batch label shape: {batch_labels.shape}")
    break

This code is using the TensorFlow Keras library to set up the ImageDataGenerator. This generator applies data augmentation techniques to image data, including rotation, width and height shifts, and horizontal flips. The generator is then fitted with training images. A training and validation generator is created from the training and validation image data with a batch size of 32. Finally, the code prints the shape of a batch of training data and labels to check the dimensions.

10.3.2 Defining the Training Loop

The training loop involves iterating over the dataset for a specified number of epochs, applying the forward diffusion process to add noise to the images, and then using the model to predict and remove this noise. During each iteration, the model's parameters are updated to minimize the loss, which is the difference between the predicted and actual noise.

Example: Training Loop

import numpy as np

# Define the number of training steps and epochs
num_steps = 10
epochs = 50

# Define a function to create step encodings
def create_step_encodings(num_samples, d_model):
    t = np.arange(num_samples).reshape(-1, 1)
    return sinusoidal_step_encoding(t, d_model)

# Training loop
for epoch in range(epochs):
    print(f"Epoch {epoch + 1}/{epochs}")
    for batch_images, _ in train_generator:
        # Apply forward diffusion to the batch images
        noisy_images = noise_layer(batch_images, training=True)

        # Create step encodings
        step_encodings = create_step_encodings(batch_images.shape[0], d_model)

        # Train the model
        loss = diffusion_model.train_on_batch([batch_images, step_encodings], batch_images)
        print(f"Loss: {loss}")

    # Validate the model on the validation set
    val_loss = 0
    for val_batch_images, _ in val_generator:
        noisy_val_images = noise_layer(val_batch_images, training=False)
        step_encodings = create_step_encodings(val_batch_images.shape[0], d_model)
        val_loss += diffusion_model.test_on_batch([val_batch_images, step_encodings], val_batch_images)
    val_loss /= len(val_generator)
    print(f"Validation Loss: {val_loss}")

This code outlines the training loop for the diffusion model. The model is trained for a specified number of epochs, with each epoch consisting of a number of steps.

In each epoch, the model is trained using the train_on_batch method on batches of images and their corresponding step encodings. The step encoding is a sinusoidal function of the timestep, and it is created using the create_step_encodings function.

The script also introduces noise to the images through the noise_layer function, and it calculates the loss of the model after each batch.

After each epoch, the model is validated on a validation set, and the average validation loss is calculated and printed.

10.3.3 Monitoring the Training Progress

To monitor the training progress, we can plot the training and validation loss over epochs. This helps us understand how well the model is learning and whether it is overfitting or underfitting the data.

Example: Monitoring Training Progress

import matplotlib.pyplot as plt

# Lists to store the training and validation loss
train_losses = []
val_losses = []

# Modified training loop to store the loss values
for epoch in range(epochs):
    print(f"Epoch {epoch + 1}/{epochs}")
    epoch_train_loss = 0
    for batch_images, _ in train_generator:
        noisy_images = noise_layer(batch_images, training=True)
        step_encodings = create_step_encodings(batch_images.shape[0], d_model)
        loss = diffusion_model.train_on_batch([batch_images, step_encodings], batch_images)
        epoch_train_loss += loss
    epoch_train_loss /= len(train_generator)
    train_losses.append(epoch_train_loss)

    val_loss = 0
    for val_batch_images, _ in val_generator:
        noisy_val_images = noise_layer(val_batch_images, training=False)
        step_encodings = create_step_encodings(val_batch_images.shape[0], d_model)
        val_loss += diffusion_model.test_on_batch([val_batch_images, step_encodings], val_batch_images)
    val_loss /= len(val_generator)
    val_losses.append(val_loss)

    print(f"Training Loss: {epoch_train_loss}")
    print(f"Validation Loss: {val_loss}")

# Plot the training and validation loss
plt.plot(train_losses, label='Training Loss')
plt.plot(val_losses, label='Validation Loss')
plt.xlabel('Epoch')
plt.ylabel('Loss')
plt.legend()
plt.title('Training and Validation Loss')
plt.show()

This code is used to train the diffusion model with a generator of training and validation data. The model is trained over a set number of epochs. For each epoch, the code introduces noise to the images, creates step encodings, and then trains the model on the noisy images. It computes the average training loss for each epoch and stores it in a list.

The same process is also done for the validation data, but instead of training, the model is tested on the validation data and the average validation loss for each epoch is recorded. Finally, it plots the training and validation losses over the epochs, allowing the user to visually assess the model's performance over time.

10.3.4 Saving the Trained Model

After training the model, it is important to save it for future use. This allows us to reuse the model without having to retrain it from scratch.

Example: Saving the Model

# Save the trained diffusion model
diffusion_model.save('diffusion_model.h5')

# Load the model later if needed
loaded_model = tf.keras.models.load_model('diffusion_model.h5')

The code is saving the trained diffusion model to a file named 'diffusion_model.h5' and then demonstrating how to load that saved model back into the program for later use.

Summary

In this section, we covered the detailed process of training the diffusion model for image generation. We started by preparing the data, including creating batches of noisy images and their corresponding denoised targets. We then defined the training loop, where we applied the forward diffusion process and used the model to predict and remove noise. We also emphasized the importance of monitoring the training progress by plotting the training and validation loss.

Finally, we discussed how to save the trained model for future use. By following these steps, you can effectively train a diffusion model to generate high-quality images from random noise. In the next sections, we will generate images using the trained model and evaluate its performance, providing a comprehensive understanding of how to apply diffusion models to real-world image generation tasks.

10.3 Training the Diffusion Model

Training the diffusion model is a crucial step in our image generation project. This process involves optimizing the model to predict and remove noise from the images, enabling it to transform random noise into coherent and structured images. In this section, we will cover the detailed process of training the diffusion model, including data preparation, training loop, and monitoring the training progress.

10.3.1 Preparing the Data

Before we start training, we need to ensure that our data is prepared and ready for the training process. This involves creating batches of noisy images and their corresponding denoised targets for the model to learn from.

Example: Data Preparation

from tensorflow.keras.preprocessing.image import ImageDataGenerator

# Define the data augmentation pipeline
datagen = ImageDataGenerator(
    rotation_range=20,
    width_shift_range=0.2,
    height_shift_range=0.2,
    horizontal_flip=True,
)

# Fit the data augmentation pipeline on the training data
datagen.fit(train_images)

# Example of creating a data generator
train_generator = datagen.flow(train_images, train_images, batch_size=32)
val_generator = datagen.flow(val_images, val_images, batch_size=32)

# Check the shape of a batch of training data
for batch_images, batch_labels in train_generator:
    print(f"Batch image shape: {batch_images.shape}")
    print(f"Batch label shape: {batch_labels.shape}")
    break

This code is using the TensorFlow Keras library to set up the ImageDataGenerator. This generator applies data augmentation techniques to image data, including rotation, width and height shifts, and horizontal flips. The generator is then fitted with training images. A training and validation generator is created from the training and validation image data with a batch size of 32. Finally, the code prints the shape of a batch of training data and labels to check the dimensions.

10.3.2 Defining the Training Loop

The training loop involves iterating over the dataset for a specified number of epochs, applying the forward diffusion process to add noise to the images, and then using the model to predict and remove this noise. During each iteration, the model's parameters are updated to minimize the loss, which is the difference between the predicted and actual noise.

Example: Training Loop

import numpy as np

# Define the number of training steps and epochs
num_steps = 10
epochs = 50

# Define a function to create step encodings
def create_step_encodings(num_samples, d_model):
    t = np.arange(num_samples).reshape(-1, 1)
    return sinusoidal_step_encoding(t, d_model)

# Training loop
for epoch in range(epochs):
    print(f"Epoch {epoch + 1}/{epochs}")
    for batch_images, _ in train_generator:
        # Apply forward diffusion to the batch images
        noisy_images = noise_layer(batch_images, training=True)

        # Create step encodings
        step_encodings = create_step_encodings(batch_images.shape[0], d_model)

        # Train the model
        loss = diffusion_model.train_on_batch([batch_images, step_encodings], batch_images)
        print(f"Loss: {loss}")

    # Validate the model on the validation set
    val_loss = 0
    for val_batch_images, _ in val_generator:
        noisy_val_images = noise_layer(val_batch_images, training=False)
        step_encodings = create_step_encodings(val_batch_images.shape[0], d_model)
        val_loss += diffusion_model.test_on_batch([val_batch_images, step_encodings], val_batch_images)
    val_loss /= len(val_generator)
    print(f"Validation Loss: {val_loss}")

This code outlines the training loop for the diffusion model. The model is trained for a specified number of epochs, with each epoch consisting of a number of steps.

In each epoch, the model is trained using the train_on_batch method on batches of images and their corresponding step encodings. The step encoding is a sinusoidal function of the timestep, and it is created using the create_step_encodings function.

The script also introduces noise to the images through the noise_layer function, and it calculates the loss of the model after each batch.

After each epoch, the model is validated on a validation set, and the average validation loss is calculated and printed.

10.3.3 Monitoring the Training Progress

To monitor the training progress, we can plot the training and validation loss over epochs. This helps us understand how well the model is learning and whether it is overfitting or underfitting the data.

Example: Monitoring Training Progress

import matplotlib.pyplot as plt

# Lists to store the training and validation loss
train_losses = []
val_losses = []

# Modified training loop to store the loss values
for epoch in range(epochs):
    print(f"Epoch {epoch + 1}/{epochs}")
    epoch_train_loss = 0
    for batch_images, _ in train_generator:
        noisy_images = noise_layer(batch_images, training=True)
        step_encodings = create_step_encodings(batch_images.shape[0], d_model)
        loss = diffusion_model.train_on_batch([batch_images, step_encodings], batch_images)
        epoch_train_loss += loss
    epoch_train_loss /= len(train_generator)
    train_losses.append(epoch_train_loss)

    val_loss = 0
    for val_batch_images, _ in val_generator:
        noisy_val_images = noise_layer(val_batch_images, training=False)
        step_encodings = create_step_encodings(val_batch_images.shape[0], d_model)
        val_loss += diffusion_model.test_on_batch([val_batch_images, step_encodings], val_batch_images)
    val_loss /= len(val_generator)
    val_losses.append(val_loss)

    print(f"Training Loss: {epoch_train_loss}")
    print(f"Validation Loss: {val_loss}")

# Plot the training and validation loss
plt.plot(train_losses, label='Training Loss')
plt.plot(val_losses, label='Validation Loss')
plt.xlabel('Epoch')
plt.ylabel('Loss')
plt.legend()
plt.title('Training and Validation Loss')
plt.show()

This code is used to train the diffusion model with a generator of training and validation data. The model is trained over a set number of epochs. For each epoch, the code introduces noise to the images, creates step encodings, and then trains the model on the noisy images. It computes the average training loss for each epoch and stores it in a list.

The same process is also done for the validation data, but instead of training, the model is tested on the validation data and the average validation loss for each epoch is recorded. Finally, it plots the training and validation losses over the epochs, allowing the user to visually assess the model's performance over time.

10.3.4 Saving the Trained Model

After training the model, it is important to save it for future use. This allows us to reuse the model without having to retrain it from scratch.

Example: Saving the Model

# Save the trained diffusion model
diffusion_model.save('diffusion_model.h5')

# Load the model later if needed
loaded_model = tf.keras.models.load_model('diffusion_model.h5')

The code is saving the trained diffusion model to a file named 'diffusion_model.h5' and then demonstrating how to load that saved model back into the program for later use.

Summary

In this section, we covered the detailed process of training the diffusion model for image generation. We started by preparing the data, including creating batches of noisy images and their corresponding denoised targets. We then defined the training loop, where we applied the forward diffusion process and used the model to predict and remove noise. We also emphasized the importance of monitoring the training progress by plotting the training and validation loss.

Finally, we discussed how to save the trained model for future use. By following these steps, you can effectively train a diffusion model to generate high-quality images from random noise. In the next sections, we will generate images using the trained model and evaluate its performance, providing a comprehensive understanding of how to apply diffusion models to real-world image generation tasks.

10.3 Training the Diffusion Model

Training the diffusion model is a crucial step in our image generation project. This process involves optimizing the model to predict and remove noise from the images, enabling it to transform random noise into coherent and structured images. In this section, we will cover the detailed process of training the diffusion model, including data preparation, training loop, and monitoring the training progress.

10.3.1 Preparing the Data

Before we start training, we need to ensure that our data is prepared and ready for the training process. This involves creating batches of noisy images and their corresponding denoised targets for the model to learn from.

Example: Data Preparation

from tensorflow.keras.preprocessing.image import ImageDataGenerator

# Define the data augmentation pipeline
datagen = ImageDataGenerator(
    rotation_range=20,
    width_shift_range=0.2,
    height_shift_range=0.2,
    horizontal_flip=True,
)

# Fit the data augmentation pipeline on the training data
datagen.fit(train_images)

# Example of creating a data generator
train_generator = datagen.flow(train_images, train_images, batch_size=32)
val_generator = datagen.flow(val_images, val_images, batch_size=32)

# Check the shape of a batch of training data
for batch_images, batch_labels in train_generator:
    print(f"Batch image shape: {batch_images.shape}")
    print(f"Batch label shape: {batch_labels.shape}")
    break

This code is using the TensorFlow Keras library to set up the ImageDataGenerator. This generator applies data augmentation techniques to image data, including rotation, width and height shifts, and horizontal flips. The generator is then fitted with training images. A training and validation generator is created from the training and validation image data with a batch size of 32. Finally, the code prints the shape of a batch of training data and labels to check the dimensions.

10.3.2 Defining the Training Loop

The training loop involves iterating over the dataset for a specified number of epochs, applying the forward diffusion process to add noise to the images, and then using the model to predict and remove this noise. During each iteration, the model's parameters are updated to minimize the loss, which is the difference between the predicted and actual noise.

Example: Training Loop

import numpy as np

# Define the number of training steps and epochs
num_steps = 10
epochs = 50

# Define a function to create step encodings
def create_step_encodings(num_samples, d_model):
    t = np.arange(num_samples).reshape(-1, 1)
    return sinusoidal_step_encoding(t, d_model)

# Training loop
for epoch in range(epochs):
    print(f"Epoch {epoch + 1}/{epochs}")
    for batch_images, _ in train_generator:
        # Apply forward diffusion to the batch images
        noisy_images = noise_layer(batch_images, training=True)

        # Create step encodings
        step_encodings = create_step_encodings(batch_images.shape[0], d_model)

        # Train the model
        loss = diffusion_model.train_on_batch([batch_images, step_encodings], batch_images)
        print(f"Loss: {loss}")

    # Validate the model on the validation set
    val_loss = 0
    for val_batch_images, _ in val_generator:
        noisy_val_images = noise_layer(val_batch_images, training=False)
        step_encodings = create_step_encodings(val_batch_images.shape[0], d_model)
        val_loss += diffusion_model.test_on_batch([val_batch_images, step_encodings], val_batch_images)
    val_loss /= len(val_generator)
    print(f"Validation Loss: {val_loss}")

This code outlines the training loop for the diffusion model. The model is trained for a specified number of epochs, with each epoch consisting of a number of steps.

In each epoch, the model is trained using the train_on_batch method on batches of images and their corresponding step encodings. The step encoding is a sinusoidal function of the timestep, and it is created using the create_step_encodings function.

The script also introduces noise to the images through the noise_layer function, and it calculates the loss of the model after each batch.

After each epoch, the model is validated on a validation set, and the average validation loss is calculated and printed.

10.3.3 Monitoring the Training Progress

To monitor the training progress, we can plot the training and validation loss over epochs. This helps us understand how well the model is learning and whether it is overfitting or underfitting the data.

Example: Monitoring Training Progress

import matplotlib.pyplot as plt

# Lists to store the training and validation loss
train_losses = []
val_losses = []

# Modified training loop to store the loss values
for epoch in range(epochs):
    print(f"Epoch {epoch + 1}/{epochs}")
    epoch_train_loss = 0
    for batch_images, _ in train_generator:
        noisy_images = noise_layer(batch_images, training=True)
        step_encodings = create_step_encodings(batch_images.shape[0], d_model)
        loss = diffusion_model.train_on_batch([batch_images, step_encodings], batch_images)
        epoch_train_loss += loss
    epoch_train_loss /= len(train_generator)
    train_losses.append(epoch_train_loss)

    val_loss = 0
    for val_batch_images, _ in val_generator:
        noisy_val_images = noise_layer(val_batch_images, training=False)
        step_encodings = create_step_encodings(val_batch_images.shape[0], d_model)
        val_loss += diffusion_model.test_on_batch([val_batch_images, step_encodings], val_batch_images)
    val_loss /= len(val_generator)
    val_losses.append(val_loss)

    print(f"Training Loss: {epoch_train_loss}")
    print(f"Validation Loss: {val_loss}")

# Plot the training and validation loss
plt.plot(train_losses, label='Training Loss')
plt.plot(val_losses, label='Validation Loss')
plt.xlabel('Epoch')
plt.ylabel('Loss')
plt.legend()
plt.title('Training and Validation Loss')
plt.show()

This code is used to train the diffusion model with a generator of training and validation data. The model is trained over a set number of epochs. For each epoch, the code introduces noise to the images, creates step encodings, and then trains the model on the noisy images. It computes the average training loss for each epoch and stores it in a list.

The same process is also done for the validation data, but instead of training, the model is tested on the validation data and the average validation loss for each epoch is recorded. Finally, it plots the training and validation losses over the epochs, allowing the user to visually assess the model's performance over time.

10.3.4 Saving the Trained Model

After training the model, it is important to save it for future use. This allows us to reuse the model without having to retrain it from scratch.

Example: Saving the Model

# Save the trained diffusion model
diffusion_model.save('diffusion_model.h5')

# Load the model later if needed
loaded_model = tf.keras.models.load_model('diffusion_model.h5')

The code is saving the trained diffusion model to a file named 'diffusion_model.h5' and then demonstrating how to load that saved model back into the program for later use.

Summary

In this section, we covered the detailed process of training the diffusion model for image generation. We started by preparing the data, including creating batches of noisy images and their corresponding denoised targets. We then defined the training loop, where we applied the forward diffusion process and used the model to predict and remove noise. We also emphasized the importance of monitoring the training progress by plotting the training and validation loss.

Finally, we discussed how to save the trained model for future use. By following these steps, you can effectively train a diffusion model to generate high-quality images from random noise. In the next sections, we will generate images using the trained model and evaluate its performance, providing a comprehensive understanding of how to apply diffusion models to real-world image generation tasks.