In [1]:
#imports
# Set Up image Ordering as theano
from keras.models import Sequential
from keras.layers import Dense
from keras.layers import Reshape
from keras.layers.core import Activation
from keras.layers.normalization import BatchNormalization
from keras.layers.convolutional import UpSampling2D
from keras.layers.convolutional import Convolution2D, MaxPooling2D
from keras.layers.core import Flatten
from keras.optimizers import SGD
from keras.datasets import mnist
import numpy as np
from PIL import Image
import argparse
import math
import keras.backend as k
k.set_image_dim_ordering('th')
import numpy as np
import matplotlib.pyplot as plt
In [15]:
# Define the Networks
def generator_model():
model = Sequential()
model.add(Dense(input_dim=100, output_dim=1024))
model.add(Activation('tanh'))
model.add(Dense(128*7*7))
model.add(BatchNormalization())
model.add(Activation('tanh'))
model.add(Reshape((128, 7, 7), input_shape=(128*7*7,)))
model.add(UpSampling2D(size=(2, 2)))
model.add(Convolution2D(64, 5, 5, border_mode='same'))
model.add(Activation('tanh'))
model.add(UpSampling2D(size=(2, 2)))
model.add(Convolution2D(1, 5, 5, border_mode='same'))
model.add(Activation('tanh'))
return model
def discriminator_model():
model = Sequential()
model.add(Convolution2D(
64, 5, 5,
border_mode='same',
input_shape=(1, 28, 28)))
model.add(Activation('tanh'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Convolution2D(128, 5, 5))
model.add(Activation('tanh'))
model.add(MaxPooling2D(pool_size=(2, 2)))
model.add(Flatten())
model.add(Dense(1024))
model.add(Activation('tanh'))
model.add(Dense(1))
model.add(Activation('sigmoid'))
return model
def generator_containing_discriminator(generator, discriminator):
model = Sequential()
model.add(generator)
discriminator.trainable = False
model.add(discriminator)
return model
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#helper
def combine_images(generated_images):
num = generated_images.shape[0]
width = int(math.sqrt(num))
height = int(math.ceil(float(num)/width))
shape = generated_images.shape[2:]
image = np.zeros((height*shape[0], width*shape[1]),
dtype=generated_images.dtype)
for index, img in enumerate(generated_images):
i = int(index/width)
j = index % width
image[i*shape[0]:(i+1)*shape[0], j*shape[1]:(j+1)*shape[1]] = \
img[0, :, :]
return image
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def train(BATCH_SIZE):
(X_train, y_train), (X_test, y_test) = mnist.load_data()
X_train = (X_train.astype(np.float32) - 127.5)/127.5
X_train = X_train.reshape((X_train.shape[0], 1) + X_train.shape[1:])
discriminator = discriminator_model()
generator = generator_model()
discriminator_on_generator = generator_containing_discriminator(generator, discriminator)
d_optim = SGD(lr=0.0005, momentum=0.9, nesterov=True)
g_optim = SGD(lr=0.0005, momentum=0.9, nesterov=True)
generator.compile(loss='binary_crossentropy', optimizer='SGD')
discriminator_on_generator.compile(loss='binary_crossentropy', optimizer=g_optim)
discriminator.trainable = True
discriminator.compile(loss='binary_crossentropy', optimizer=d_optim)
noise = np.zeros((BATCH_SIZE, 100))
for epoch in range(100):
print("Epoch is", epoch)
print("Number of batches", int(X_train.shape[0]/BATCH_SIZE))
for index in range(int(X_train.shape[0]/BATCH_SIZE)):
for i in range(BATCH_SIZE):
noise[i, :] = np.random.uniform(-1, 1, 100)
image_batch = X_train[index*BATCH_SIZE:(index+1)*BATCH_SIZE]
generated_images = generator.predict(noise, verbose=0)
if index % 20 == 0:
image = combine_images(generated_images)
image = image*127.5+127.5
Image.fromarray(image.astype(np.uint8)).save(
str(epoch)+"_"+str(index)+".png")
X = np.concatenate((image_batch, generated_images))
y = [1] * BATCH_SIZE + [0] * BATCH_SIZE
d_loss = discriminator.train_on_batch(X, y)
print("batch %d d_loss : %f" % (index, d_loss))
for i in range(BATCH_SIZE):
noise[i, :] = np.random.uniform(-1, 1, 100)
discriminator.trainable = False
g_loss = discriminator_on_generator.train_on_batch(
noise, [1] * BATCH_SIZE)
discriminator.trainable = True
print("batch %d g_loss : %f" % (index, g_loss))
if index % 10 == 9:
generator.save_weights('generator', True)
discriminator.save_weights('discriminator', True)
In [3]:
def generate(BATCH_SIZE, nice=True):
generator = generator_model()
generator.compile(loss='binary_crossentropy', optimizer="SGD")
generator.load_weights('generator')
if nice:
discriminator = discriminator_model()
discriminator.compile(loss='binary_crossentropy', optimizer="SGD")
discriminator.load_weights('discriminator')
noise = np.zeros((BATCH_SIZE*20, 100))
for i in range(BATCH_SIZE*20):
noise[i, :] = np.random.uniform(-1, 1, 100)
generated_images = generator.predict(noise, verbose=1)
d_pret = discriminator.predict(generated_images, verbose=1)
index = np.arange(0, BATCH_SIZE*20)
index.resize((BATCH_SIZE*20, 1))
pre_with_index = list(np.append(d_pret, index, axis=1))
pre_with_index.sort(key=lambda x: x[0], reverse=True)
nice_images = np.zeros((BATCH_SIZE, 1) +
(generated_images.shape[2:]), dtype=np.float32)
for i in range(int(BATCH_SIZE)):
idx = int(pre_with_index[i][1])
nice_images[i, 0, :, :] = generated_images[idx, 0, :, :]
image = combine_images(nice_images)
else:
noise = np.zeros((BATCH_SIZE, 100))
for i in range(BATCH_SIZE):
noise[i, :] = np.random.uniform(-1, 1, 100)
generated_images = generator.predict(noise, verbose=1)
image = combine_images(generated_images)
image = image*127.5+127.5
Image.fromarray(image.astype(np.uint8)).save(
"generated_image.png")
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train(128)
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