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deep-learning-with-python-n…/chapter12_part05_gans.ipynb
2021-06-05 20:28:07 -07:00

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{
"cells": [
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"This is a companion notebook for the book [Deep Learning with Python, Second Edition](https://www.manning.com/books/deep-learning-with-python-second-edition?a_aid=keras&a_bid=76564dff). For readability, it only contains runnable code blocks and section titles, and omits everything else in the book: text paragraphs, figures, and pseudocode.\n\n**If you want to be able to follow what's going on, I recommend reading the notebook side by side with your copy of the book.**\n\nThis notebook was generated for TensorFlow 2.6."
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"## Introduction to generative adversarial networks"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"### A schematic GAN implementation"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"### A bag of tricks"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"### Getting our hands on the CelebA dataset"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"**Getting the CelebA data**"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"!mkdir celeba_gan\n",
"!gdown --id 1O7m1010EJjLE5QxLZiM9Fpjs7Oj6e684 -O celeba_gan/data.zip\n",
"!unzip -qq celeba_gan/data.zip -d celeba_gan"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"**Creating a Dataset from a directory of images**"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"from tensorflow import keras\n",
"dataset = keras.preprocessing.image_dataset_from_directory(\n",
" \"celeba_gan\",\n",
" label_mode=None,\n",
" image_size=(64, 64),\n",
" batch_size=32,\n",
" smart_resize=True)"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"**Rescaling the images**"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"dataset = dataset.map(lambda x: x / 255.)"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"**Displaying the first image**"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"import matplotlib.pyplot as plt\n",
"for x in dataset:\n",
" plt.axis(\"off\")\n",
" plt.imshow((x.numpy() * 255).astype(\"int32\")[0])\n",
" break"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"### The discriminator"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"**The GAN discriminator network**"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"from tensorflow.keras import layers\n",
"\n",
"discriminator = keras.Sequential(\n",
" [\n",
" keras.Input(shape=(64, 64, 3)),\n",
" layers.Conv2D(64, kernel_size=4, strides=2, padding=\"same\"),\n",
" layers.LeakyReLU(alpha=0.2),\n",
" layers.Conv2D(128, kernel_size=4, strides=2, padding=\"same\"),\n",
" layers.LeakyReLU(alpha=0.2),\n",
" layers.Conv2D(128, kernel_size=4, strides=2, padding=\"same\"),\n",
" layers.LeakyReLU(alpha=0.2),\n",
" layers.Flatten(),\n",
" layers.Dropout(0.2),\n",
" layers.Dense(1, activation=\"sigmoid\"),\n",
" ],\n",
" name=\"discriminator\",\n",
")"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"discriminator.summary()"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"### The generator"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"**GAN generator network**"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"latent_dim = 128\n",
"\n",
"generator = keras.Sequential(\n",
" [\n",
" keras.Input(shape=(latent_dim,)),\n",
" layers.Dense(8 * 8 * 128),\n",
" layers.Reshape((8, 8, 128)),\n",
" layers.Conv2DTranspose(128, kernel_size=4, strides=2, padding=\"same\"),\n",
" layers.LeakyReLU(alpha=0.2),\n",
" layers.Conv2DTranspose(256, kernel_size=4, strides=2, padding=\"same\"),\n",
" layers.LeakyReLU(alpha=0.2),\n",
" layers.Conv2DTranspose(512, kernel_size=4, strides=2, padding=\"same\"),\n",
" layers.LeakyReLU(alpha=0.2),\n",
" layers.Conv2D(3, kernel_size=5, padding=\"same\", activation=\"sigmoid\"),\n",
" ],\n",
" name=\"generator\",\n",
")"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"generator.summary()"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"### The adversarial network"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"**The GAN Model**"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"class GAN(keras.Model):\n",
" def __init__(self, discriminator, generator, latent_dim):\n",
" super().__init__()\n",
" self.discriminator = discriminator\n",
" self.generator = generator\n",
" self.latent_dim = latent_dim\n",
" self.d_loss_metric = keras.metrics.Mean(name=\"d_loss\")\n",
" self.g_loss_metric = keras.metrics.Mean(name=\"g_loss\")\n",
"\n",
" def compile(self, d_optimizer, g_optimizer, loss_fn):\n",
" super(GAN, self).compile()\n",
" self.d_optimizer = d_optimizer\n",
" self.g_optimizer = g_optimizer\n",
" self.loss_fn = loss_fn\n",
"\n",
" @property\n",
" def metrics(self):\n",
" return [self.d_loss_metric, self.g_loss_metric]\n",
"\n",
" def train_step(self, real_images):\n",
" batch_size = tf.shape(real_images)[0]\n",
" random_latent_vectors = tf.random.normal(shape=(batch_size, self.latent_dim))\n",
" generated_images = self.generator(random_latent_vectors)\n",
" combined_images = tf.concat([generated_images, real_images], axis=0)\n",
" labels = tf.concat(\n",
" [tf.ones((batch_size, 1)), tf.zeros((batch_size, 1))], axis=0\n",
" )\n",
" labels += 0.05 * tf.random.uniform(tf.shape(labels))\n",
"\n",
" with tf.GradientTape() as tape:\n",
" predictions = self.discriminator(combined_images)\n",
" d_loss = self.loss_fn(labels, predictions)\n",
" grads = tape.gradient(d_loss, self.discriminator.trainable_weights)\n",
" self.d_optimizer.apply_gradients(\n",
" zip(grads, self.discriminator.trainable_weights)\n",
" )\n",
"\n",
" random_latent_vectors = tf.random.normal(\n",
" shape=(batch_size, self.latent_dim))\n",
"\n",
" misleading_labels = tf.zeros((batch_size, 1))\n",
"\n",
" with tf.GradientTape() as tape:\n",
" predictions = self.discriminator(self.generator(random_latent_vectors))\n",
" g_loss = self.loss_fn(misleading_labels, predictions)\n",
" grads = tape.gradient(g_loss, self.generator.trainable_weights)\n",
" self.g_optimizer.apply_gradients(zip(grads, self.generator.trainable_weights))\n",
"\n",
" self.d_loss_metric.update_state(d_loss)\n",
" self.g_loss_metric.update_state(g_loss)\n",
" return {\"d_loss\": self.d_loss_metric.result(), \"g_loss\": self.g_loss_metric.result()}"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"**A callback to sample generated images during training**"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"class GANMonitor(keras.callbacks.Callback):\n",
" def __init__(self, num_img=3, latent_dim=128):\n",
" self.num_img = num_img\n",
" self.latent_dim = latent_dim\n",
"\n",
" def on_epoch_end(self, epoch, logs=None):\n",
" random_latent_vectors = tf.random.normal(shape=(self.num_img, self.latent_dim))\n",
" generated_images = self.model.generator(random_latent_vectors)\n",
" generated_images *= 255\n",
" generated_images.numpy()\n",
" for i in range(self.num_img):\n",
" img = keras.preprocessing.image.array_to_img(generated_images[i])\n",
" img.save(f\"generated_img_{epoch:03d}_{i}.png\")"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"**Compiling and training the GAN**"
]
},
{
"cell_type": "code",
"execution_count": 0,
"metadata": {
"colab_type": "code"
},
"outputs": [],
"source": [
"epochs = 100\n",
"\n",
"gan = GAN(discriminator=discriminator, generator=generator, latent_dim=latent_dim)\n",
"gan.compile(\n",
" d_optimizer=keras.optimizers.Adam(learning_rate=0.0001),\n",
" g_optimizer=keras.optimizers.Adam(learning_rate=0.0001),\n",
" loss_fn=keras.losses.BinaryCrossentropy(),\n",
")\n",
"\n",
"gan.fit(\n",
" dataset, epochs=epochs, callbacks=[GANMonitor(num_img=10, latent_dim=latent_dim)]\n",
")"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"### Wrapping up"
]
},
{
"cell_type": "markdown",
"metadata": {
"colab_type": "text"
},
"source": [
"## Chapter summary"
]
}
],
"metadata": {
"colab": {
"collapsed_sections": [],
"name": "chapter12_part05_gans.i",
"private_outputs": false,
"provenance": [],
"toc_visible": true
},
"kernelspec": {
"display_name": "Python 3",
"language": "python",
"name": "python3"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
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"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
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