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| 1 | +import os |
| 2 | +import numpy as np |
| 3 | + |
| 4 | +from keras.layers import Input |
| 5 | +from keras.models import Model, Sequential |
| 6 | +from keras.layers.core import Reshape, Dense, Dropout, Flatten |
| 7 | +from keras.layers.advanced_activations import LeakyReLU |
| 8 | +from keras.layers.convolutional import Convolution2D, UpSampling2D |
| 9 | +from keras.layers.normalization import BatchNormalization |
| 10 | +from keras.datasets import mnist |
| 11 | +from keras.optimizers import Adam |
| 12 | +from keras import backend as K |
| 13 | +from keras import initializers |
| 14 | +from PIL import Image |
| 15 | +from keras.callbacks import LambdaCallback |
| 16 | +import wandb |
| 17 | + |
| 18 | +# Find more tricks here: https://github.com/soumith/ganhacks |
| 19 | + |
| 20 | +run = wandb.init() |
| 21 | +config = wandb.config |
| 22 | + |
| 23 | +# The results are a little better when the dimensionality of the random vector is only 10. |
| 24 | +# The dimensionality has been left at 100 for consistency with other GAN implementations. |
| 25 | +randomDim = 10 |
| 26 | + |
| 27 | +# Load MNIST data |
| 28 | +(X_train, y_train), (X_test, y_test) = mnist.load_data() |
| 29 | +X_train = (X_train.astype(np.float32) - 127.5)/127.5 |
| 30 | +X_train = X_train.reshape(60000, 784) |
| 31 | + |
| 32 | +config.lr=0.0002 |
| 33 | +config.beta_1=0.5 |
| 34 | +config.batch_size=128 |
| 35 | +config.epochs=10 |
| 36 | + |
| 37 | +# Optimizer |
| 38 | +adam = Adam(config.lr, beta_1=config.beta_1) |
| 39 | + |
| 40 | +generator = Sequential() |
| 41 | +generator.add(Dense(256, input_dim=randomDim, kernel_initializer=initializers.RandomNormal(stddev=0.02))) |
| 42 | +generator.add(LeakyReLU(0.2)) |
| 43 | +generator.add(Dense(512)) |
| 44 | +generator.add(LeakyReLU(0.2)) |
| 45 | +generator.add(Dense(1024)) |
| 46 | +generator.add(LeakyReLU(0.2)) |
| 47 | +generator.add(Dense(784, activation='tanh')) |
| 48 | +generator.compile(loss='binary_crossentropy', optimizer=adam, metrics=['acc']) |
| 49 | + |
| 50 | +discriminator = Sequential() |
| 51 | +discriminator.add(Dense(1024, input_dim=784, kernel_initializer=initializers.RandomNormal(stddev=0.02))) |
| 52 | +discriminator.add(LeakyReLU(0.2)) |
| 53 | +discriminator.add(Dropout(0.3)) |
| 54 | +discriminator.add(Dense(512)) |
| 55 | +discriminator.add(LeakyReLU(0.2)) |
| 56 | +discriminator.add(Dropout(0.3)) |
| 57 | +discriminator.add(Dense(256)) |
| 58 | +discriminator.add(LeakyReLU(0.2)) |
| 59 | +discriminator.add(Dropout(0.3)) |
| 60 | +discriminator.add(Dense(1, activation='sigmoid')) |
| 61 | +discriminator.compile(loss='binary_crossentropy', optimizer=adam, metrics=['binary_accuracy']) |
| 62 | + |
| 63 | +# Combined network |
| 64 | +discriminator.trainable = False |
| 65 | +ganInput = Input(shape=(randomDim,)) |
| 66 | +x = generator(ganInput) |
| 67 | +ganOutput = discriminator(x) |
| 68 | +gan = Model(inputs=ganInput, outputs=ganOutput) |
| 69 | +gan.compile(loss='binary_crossentropy', optimizer=adam, metrics = ['binary_accuracy']) |
| 70 | + |
| 71 | +iter = 0 |
| 72 | +# Write out generated MNIST images |
| 73 | +def writeGeneratedImages(epoch, examples=100, dim=(10, 10), figsize=(10, 10)): |
| 74 | + noise = np.random.normal(0, 1, size=[examples, randomDim]) |
| 75 | + generatedImages = generator.predict(noise) |
| 76 | + generatedImages = generatedImages.reshape(examples, 28, 28) |
| 77 | + |
| 78 | + for i in range(10): |
| 79 | + img = Image.fromarray((generatedImages[0] + 1.)* (255/2.)) |
| 80 | + img = img.convert('RGB') |
| 81 | + img.save(str(i) + ".jpg") |
| 82 | + |
| 83 | + |
| 84 | +# Save the generator and discriminator networks (and weights) for later use |
| 85 | +def saveModels(epoch): |
| 86 | + generator.save('models/gan_generator_epoch_%d.h5' % epoch) |
| 87 | + discriminator.save('models/gan_discriminator_epoch_%d.h5' % epoch) |
| 88 | + |
| 89 | + |
| 90 | +def log_generator(epoch, logs): |
| 91 | + global iter |
| 92 | + iter += 1 |
| 93 | + if iter % 500 == 0: |
| 94 | + wandb.log({'generator_loss': logs['loss'], |
| 95 | + 'generator_acc': logs['binary_accuracy'], |
| 96 | + 'discriminator_loss': 0.0, |
| 97 | + 'discriminator_acc': (1-logs['binary_accuracy'])}) |
| 98 | + |
| 99 | +def log_discriminator(epoch, logs): |
| 100 | + global iter |
| 101 | + if iter % 500 == 250: |
| 102 | + wandb.log({ |
| 103 | + 'generator_loss': 0.0, |
| 104 | + 'generator_acc': logs['binary_accuracy'], |
| 105 | + 'discriminator_loss': logs['loss'], |
| 106 | + 'discriminator_acc': logs['binary_accuracy']}) |
| 107 | + |
| 108 | +def train(epochs=config.epochs, batchSize=config.batch_size): |
| 109 | + batchCount = int(X_train.shape[0] / config.batch_size) |
| 110 | + print('Epochs:', epochs) |
| 111 | + print('Batch size:', batchSize) |
| 112 | + print('Batches per epoch:', batchCount) |
| 113 | + |
| 114 | + wandb_logging_callback_d = LambdaCallback(on_epoch_end=log_discriminator) |
| 115 | + wandb_logging_callback_g = LambdaCallback(on_epoch_end=log_generator) |
| 116 | + |
| 117 | + |
| 118 | + for e in range(1, epochs+1): |
| 119 | + print("Epoch {}:".format(e)) |
| 120 | + for i in range(batchCount): |
| 121 | + # Get a random set of input noise and images |
| 122 | + noise = np.random.normal(0, 1, size=[batchSize, randomDim]) |
| 123 | + imageBatch = X_train[np.random.randint(0, X_train.shape[0], size=batchSize)] |
| 124 | + |
| 125 | + # Generate fake MNIST images |
| 126 | + generatedImages = generator.predict(noise) |
| 127 | + # print np.shape(imageBatch), np.shape(generatedImages) |
| 128 | + X = np.concatenate([imageBatch, generatedImages]) |
| 129 | + |
| 130 | + # Labels for generated and real data |
| 131 | + yDis = np.zeros(2*batchSize) |
| 132 | + # One-sided label smoothing |
| 133 | + yDis[:batchSize] = 0.9 |
| 134 | + |
| 135 | + # Train discriminator |
| 136 | + discriminator.trainable = True |
| 137 | + dloss = discriminator.fit(X, yDis, verbose=0, callbacks=[wandb_logging_callback_d]) |
| 138 | + |
| 139 | + # Train generator |
| 140 | + noise = np.random.normal(0, 1, size=[batchSize, randomDim]) |
| 141 | + yGen = np.ones(batchSize) |
| 142 | + discriminator.trainable = False |
| 143 | + gloss = gan.fit(noise, yGen, verbose=0, callbacks=[wandb_logging_callback_g]) |
| 144 | + |
| 145 | + writeGeneratedImages(i) |
| 146 | + |
| 147 | + print("Discriminator loss: {}, acc: {}".format(dloss.history["loss"][-1], dloss.history["binary_accuracy"][-1])) |
| 148 | + print("Generator loss: {}, acc: {}".format(gloss.history["loss"][-1], 1-gloss.history["binary_accuracy"][-1])) |
| 149 | + |
| 150 | + |
| 151 | +if __name__ == '__main__': |
| 152 | + train(200, 128) |
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