In this project, you'll use generative adversarial networks to generate new images of faces.
You'll be using two datasets in this project:
Since the celebA dataset is complex and you're doing GANs in a project for the first time, we want you to test your neural network on MNIST before CelebA. Running the GANs on MNIST will allow you to see how well your model trains sooner.
If you're using FloydHub, set data_dir to "/input" and use the FloydHub data ID "R5KrjnANiKVhLWAkpXhNBe".
In [1]:
data_dir = './data'
# FloydHub - Use with data ID "R5KrjnANiKVhLWAkpXhNBe"
data_dir = '/input'
"""
DON'T MODIFY ANYTHING IN THIS CELL
"""
import helper
helper.download_extract('mnist', data_dir)
helper.download_extract('celeba', data_dir)
As you're aware, the MNIST dataset contains images of handwritten digits. You can view the first number of examples by changing show_n_images.
In [2]:
show_n_images = 25
"""
DON'T MODIFY ANYTHING IN THIS CELL
"""
%matplotlib inline
import os
from glob import glob
from matplotlib import pyplot
mnist_images = helper.get_batch(glob(os.path.join(data_dir, 'mnist/*.jpg'))[:show_n_images], 28, 28, 'L')
pyplot.imshow(helper.images_square_grid(mnist_images, 'L'), cmap='gray')
Out[2]:
The CelebFaces Attributes Dataset (CelebA) dataset contains over 200,000 celebrity images with annotations. Since you're going to be generating faces, you won't need the annotations. You can view the first number of examples by changing show_n_images.
In [3]:
show_n_images = 25
"""
DON'T MODIFY ANYTHING IN THIS CELL
"""
mnist_images = helper.get_batch(glob(os.path.join(data_dir, 'img_align_celeba/*.jpg'))[:show_n_images], 28, 28, 'RGB')
pyplot.imshow(helper.images_square_grid(mnist_images, 'RGB'))
Out[3]:
Since the project's main focus is on building the GANs, we'll preprocess the data for you. The values of the MNIST and CelebA dataset will be in the range of -0.5 to 0.5 of 28x28 dimensional images. The CelebA images will be cropped to remove parts of the image that don't include a face, then resized down to 28x28.
The MNIST images are black and white images with a single color channel while the CelebA images have 3 color channels (RGB color channel).
You'll build the components necessary to build a GANs by implementing the following functions below:
model_inputsdiscriminatorgeneratormodel_lossmodel_opttrainThis will check to make sure you have the correct version of TensorFlow and access to a GPU
In [4]:
"""
DON'T MODIFY ANYTHING IN THIS CELL
"""
from distutils.version import LooseVersion
import warnings
import tensorflow as tf
# Check TensorFlow Version
assert LooseVersion(tf.__version__) >= LooseVersion('1.0'), 'Please use TensorFlow version 1.0 or newer. You are using {}'.format(tf.__version__)
print('TensorFlow Version: {}'.format(tf.__version__))
# Check for a GPU
if not tf.test.gpu_device_name():
warnings.warn('No GPU found. Please use a GPU to train your neural network.')
else:
print('Default GPU Device: {}'.format(tf.test.gpu_device_name()))
Implement the model_inputs function to create TF Placeholders for the Neural Network. It should create the following placeholders:
image_width, image_height, and image_channels.z_dim.Return the placeholders in the following the tuple (tensor of real input images, tensor of z data)
In [5]:
import problem_unittests as tests
def model_inputs(image_width, image_height, image_channels, z_dim):
"""
Create the model inputs
:param image_width: The input image width
:param image_height: The input image height
:param image_channels: The number of image channels
:param z_dim: The dimension of Z
:return: Tuple of (tensor of real input images, tensor of z data, learning rate)
"""
real_input = tf.placeholder(tf.float32, [None, image_width, image_height, image_channels], name="real_input")
z_input = tf.placeholder(tf.float32, [None, z_dim], name="z_input")
learning_rate = tf.placeholder(tf.float32, name="learning_rate")
return real_input, z_input, learning_rate
"""
DON'T MODIFY ANYTHING IN THIS CELL THAT IS BELOW THIS LINE
"""
tests.test_model_inputs(model_inputs)
Implement discriminator to create a discriminator neural network that discriminates on images. This function should be able to reuse the variabes in the neural network. Use tf.variable_scope with a scope name of "discriminator" to allow the variables to be reused. The function should return a tuple of (tensor output of the discriminator, tensor logits of the discriminator).
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def leaky_relu(input, alpha=0.2, name="leaky_relu"):
return tf.maximum(input, alpha * input, name=name)
In [7]:
def discriminator(images, reuse=False, keep_prob=0.9):
"""
Create the discriminator network
:param image: Tensor of input image(s)
:param reuse: Boolean if the weights should be reused
:return: Tuple of (tensor output of the discriminator, tensor logits of the discriminator)
"""
with tf.variable_scope("discriminator", reuse=reuse):
# convert 28x28x(input_dimension) into 14x14x64
layer1 = tf.layers.conv2d(images, 64, 5, 2, 'same', kernel_initializer=tf.contrib.layers.xavier_initializer(True))
layer1 = leaky_relu(layer1)
#layer1 = tf.nn.dropout(layer1, keep_prob=keep_prob)
#layer1 = tf.Print(layer1, [tf.shape(layer1)], "discriminator layer 1 shape", summarize=100)
# convert 14x14x64 into 7x7x128
layer2 = tf.layers.conv2d(layer1, 128, 5, 2, 'same', kernel_initializer=tf.contrib.layers.xavier_initializer(True))
layer2 = tf.layers.batch_normalization(layer2, training=True)
layer2 = leaky_relu(layer2)
#layer2 = tf.nn.dropout(layer2, keep_prob=keep_prob)
#layer2 = tf.Print(layer2, [tf.shape(layer2)], "discriminator layer 2 shape", summarize=100)
# removed a layer as suggested by reviewer
# convert 7x7x128 into 4x4x256
layer3 = tf.layers.conv2d(layer2, 256, 5, 2, 'same', kernel_initializer=tf.contrib.layers.xavier_initializer(True))
layer3 = tf.layers.batch_normalization(layer3, training=True)
layer3 = leaky_relu(layer3)
#layer3 = tf.maximum(alpha * layer3, layer3)
#layer3 = tf.nn.dropout(layer3, keep_prob=keep_prob)
#layer3 = tf.Print(layer3, [tf.shape(layer3)], "discriminator layer 3 shape", summarize=100)
# flatten to linear array
convolutions_output = tf.reshape(layer2, (-1, 4 * 4 * 256))
logits = tf.layers.dense(convolutions_output, 1) # 1 single output
output = tf.sigmoid(logits)
return logits, output
"""
DON'T MODIFY ANYTHING IN THIS CELL THAT IS BELOW THIS LINE
"""
tests.test_discriminator(discriminator, tf)
Implement generator to generate an image using z. This function should be able to reuse the variabes in the neural network. Use tf.variable_scope with a scope name of "generator" to allow the variables to be reused. The function should return the generated 28 x 28 x out_channel_dim images.
In [11]:
def generator(z, out_channel_dim, is_train=True, keep_prob=0.5):
"""
Create the generator network
:param z: Input z
:param out_channel_dim: The number of channels in the output image
:param is_train: Boolean if generator is being used for training
:return: The tensor output of the generator
"""
reuse = not is_train
with tf.variable_scope('generator', reuse=reuse):
# transform input into a tensor of 4x4x256
layer1 = tf.layers.dense(z, 4 * 4 * 256)
layer1 = tf.reshape(layer1, (-1, 4, 4, 256))
layer1 = tf.layers.batch_normalization(layer1, training=is_train)
layer1 = leaky_relu(layer1)
#layer1 = tf.nn.dropout(layer1, keep_prob=keep_prob)
#layer1 = tf.Print(layer1, [tf.shape(layer1)], "generator layer 1 shape", summarize=100)
# convert 4x4x256 into 8x8x128
layer2 = tf.layers.conv2d_transpose(layer1, 128, 4, 1, 'valid', kernel_initializer=tf.contrib.layers.xavier_initializer(True))
layer2 = tf.layers.batch_normalization(layer2, training=is_train)
layer2 = leaky_relu(layer2)
#layer2 = tf.nn.dropout(layer2, keep_prob=keep_prob)
#layer2 = tf.Print(layer2, [tf.shape(layer2)], "generator layer 2 shape", summarize=100)
# convert 8x8x128 into 16x16x64
layer3 = tf.layers.conv2d_transpose(layer2, 64, 5, 2, 'same', kernel_initializer=tf.contrib.layers.xavier_initializer(True))
layer3 = tf.layers.batch_normalization(layer3, training=is_train)
layer3 = leaky_relu(layer3)
#layer3 = tf.nn.dropout(layer3, keep_prob=keep_prob)
#layer3 = tf.Print(layer3, [tf.shape(layer3)], "generator layer 3 shape", summarize=100)
# convert 16x16x64 into 32x32x(out_channel_dim)
logits = tf.layers.conv2d_transpose(layer3, out_channel_dim, 5, 2, 'same', kernel_initializer=tf.contrib.layers.xavier_initializer(True))
#layer4 = tf.Print(logits, [tf.shape(logits)], "generator logits shape", summarize=100)
output = tf.tanh(logits)
return output
"""
DON'T MODIFY ANYTHING IN THIS CELL THAT IS BELOW THIS LINE
"""
tests.test_generator(generator, tf)
In [12]:
def model_loss(input_real, input_z, out_channel_dim):
"""
Get the loss for the discriminator and generator
:param input_real: Images from the real dataset
:param input_z: Z input
:param out_channel_dim: The number of channels in the output image
:return: A tuple of (discriminator loss, generator loss)
"""
generator_network = generator(input_z, out_channel_dim, is_train=True)
discriminator_real_network, discriminator_real_logits = discriminator(input_real, reuse=False)
discriminator_fake_network, discriminator_fake_logits = discriminator(generator_network, reuse=True)
discriminator_real_loss = tf.reduce_mean(tf.nn.sigmoid_cross_entropy_with_logits(
logits=discriminator_real_logits,
labels=tf.ones_like(discriminator_real_network) * 0.9 # smooth real labels
))
discriminator_fake_loss = tf.reduce_mean(tf.nn.sigmoid_cross_entropy_with_logits(
logits=discriminator_fake_logits,
labels=tf.zeros_like(discriminator_fake_network)
))
generator_loss = tf.reduce_mean(tf.nn.sigmoid_cross_entropy_with_logits(
logits=discriminator_fake_logits,
labels=tf.ones_like(discriminator_fake_network)
))
discriminator_loss = discriminator_real_loss + discriminator_fake_loss
return discriminator_loss, generator_loss
"""
DON'T MODIFY ANYTHING IN THIS CELL THAT IS BELOW THIS LINE
"""
tests.test_model_loss(model_loss)
Implement model_opt to create the optimization operations for the GANs. Use tf.trainable_variables to get all the trainable variables. Filter the variables with names that are in the discriminator and generator scope names. The function should return a tuple of (discriminator training operation, generator training operation).
In [13]:
def model_opt(d_loss, g_loss, learning_rate, beta1):
"""
Get optimization operations
:param d_loss: Discriminator loss Tensor
:param g_loss: Generator loss Tensor
:param learning_rate: Learning Rate Placeholder
:param beta1: The exponential decay rate for the 1st moment in the optimizer
:return: A tuple of (discriminator training operation, generator training operation)
"""
trainable_variables = tf.trainable_variables()
discriminator_variables = [variable for variable in trainable_variables if variable.name.startswith('discriminator')]
generator_variables = [variable for variable in trainable_variables if variable.name.startswith('generator')]
# choo chooo
discriminator_train = tf.train.AdamOptimizer(learning_rate, beta1=beta1).minimize(d_loss, var_list=discriminator_variables)
with tf.control_dependencies(tf.get_collection(tf.GraphKeys.UPDATE_OPS, scope='generator')):
generator_train = tf.train.AdamOptimizer(learning_rate, beta1=beta1).minimize(g_loss, var_list=generator_variables)
return discriminator_train, generator_train
"""
DON'T MODIFY ANYTHING IN THIS CELL THAT IS BELOW THIS LINE
"""
tests.test_model_opt(model_opt, tf)
In [14]:
"""
DON'T MODIFY ANYTHING IN THIS CELL
"""
import numpy as np
def show_generator_output(sess, n_images, input_z, out_channel_dim, image_mode):
"""
Show example output for the generator
:param sess: TensorFlow session
:param n_images: Number of Images to display
:param input_z: Input Z Tensor
:param out_channel_dim: The number of channels in the output image
:param image_mode: The mode to use for images ("RGB" or "L")
"""
cmap = None if image_mode == 'RGB' else 'gray'
z_dim = input_z.get_shape().as_list()[-1]
example_z = np.random.uniform(-1, 1, size=[n_images, z_dim])
samples = sess.run(
generator(input_z, out_channel_dim, False),
feed_dict={input_z: example_z})
images_grid = helper.images_square_grid(samples, image_mode)
pyplot.imshow(images_grid, cmap=cmap)
pyplot.show()
Implement train to build and train the GANs. Use the following functions you implemented:
model_inputs(image_width, image_height, image_channels, z_dim)model_loss(input_real, input_z, out_channel_dim)model_opt(d_loss, g_loss, learning_rate, beta1)Use the show_generator_output to show generator output while you train. Running show_generator_output for every batch will drastically increase training time and increase the size of the notebook. It's recommended to print the generator output every 100 batches.
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def train(epoch_count, batch_size, z_dim, learning_rate, beta1, get_batches, data_shape, data_image_mode):
"""
Train the GAN
:param epoch_count: Number of epochs
:param batch_size: Batch Size
:param z_dim: Z dimension
:param learning_rate: Learning Rate
:param beta1: The exponential decay rate for the 1st moment in the optimizer
:param get_batches: Function to get batches
:param data_shape: Shape of the data
:param data_image_mode: The image mode to use for images ("RGB" or "L")
"""
image_width = data_shape[1]
image_height = data_shape[2]
image_channels = data_shape[3]
input_real, input_z, learning_rate_tensor = model_inputs(image_width, image_height, image_channels, z_dim)
discriminator_loss, generator_loss = model_loss(input_real, input_z, image_channels)
discriminator_training, generator_training = model_opt(discriminator_loss, generator_loss, learning_rate, beta1)
with tf.Session() as sess:
sess.run(tf.global_variables_initializer())
for epoch_i in range(epoch_count):
iterations = 0
for batch_images in get_batches(batch_size):
batch_images = batch_images * 2.0 # normalize to -1, 1
iterations += 1
#batch_z_input = np.random.normal(0, scale=1.0, size=(batch_size, z_dim))
batch_z_input = np.random.uniform(-1, 1, size=(batch_size, z_dim))
network_feed_dict = {
input_real: batch_images,
input_z: batch_z_input,
learning_rate_tensor: learning_rate
}
_ = sess.run(discriminator_training, feed_dict=network_feed_dict)
_ = sess.run(generator_training, feed_dict=network_feed_dict)
if iterations % 10 == 0:
training_loss_discriminator = discriminator_loss.eval(network_feed_dict)
training_loss_generator = generator_loss.eval(network_feed_dict)
print("Iteration {:3} -- Epoch {}/{} -- Discriminator loss: {:5.5f} -- Generator loss: {:5.5f}".format(
iterations,
epoch_i + 1,
epoch_count,
training_loss_discriminator,
training_loss_generator
))
if iterations % 100 == 0:
show_generator_output(sess, show_n_images, input_z, image_channels, data_image_mode)
show_generator_output(sess, show_n_images, input_z, image_channels, data_image_mode)
print("Done!")
In [17]:
batch_size = 64
z_dim = 100
learning_rate = 0.0002
beta1 = 0.5
"""
DON'T MODIFY ANYTHING IN THIS CELL THAT IS BELOW THIS LINE
"""
epochs = 2
mnist_dataset = helper.Dataset('mnist', glob(os.path.join(data_dir, 'mnist/*.jpg')))
with tf.Graph().as_default():
train(epochs, batch_size, z_dim, learning_rate, beta1, mnist_dataset.get_batches,
mnist_dataset.shape, mnist_dataset.image_mode)
In [18]:
batch_size = 32
z_dim = 128
learning_rate = 0.0002
beta1 = 0.5
"""
DON'T MODIFY ANYTHING IN THIS CELL THAT IS BELOW THIS LINE
"""
epochs = 1
celeba_dataset = helper.Dataset('celeba', glob(os.path.join(data_dir, 'img_align_celeba/*.jpg')))
with tf.Graph().as_default():
train(epochs, batch_size, z_dim, learning_rate, beta1, celeba_dataset.get_batches,
celeba_dataset.shape, celeba_dataset.image_mode)