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+from __future__ import print_function, division
+
+from keras.datasets import mnist
+from keras.layers import Input, Dense, Reshape, Flatten, Dropout, multiply
+from keras.layers import BatchNormalization, Activation, Embedding, ZeroPadding2D
+from keras.layers.advanced_activations import LeakyReLU
+from keras.layers.convolutional import UpSampling2D, Conv2D
+from keras.models import Sequential, Model
+from keras.optimizers import Adam
+import matplotlib.pyplot as plt
+
+import numpy as np
+
+class CGAN():
+ def __init__(self):
+ # Input shape
+ self.img_rows = 28
+ self.img_cols = 28
+ self.channels = 1
+ self.img_shape = (self.img_rows, self.img_cols, self.channels)
+ self.num_classes = 10
+ self.latent_dim = 100
+
+ optimizer = Adam(0.0002, 0.5)
+
+ # Build and compile the discriminator
+ self.discriminator = self.build_discriminator()
+ self.discriminator.compile(loss=['binary_crossentropy'],
+ optimizer=optimizer,
+ metrics=['accuracy'])
+
+ # Build the generator
+ self.generator = self.build_generator()
+
+ # The generator takes noise and the target label as input
+ # and generates the corresponding digit of that label
+ noise = Input(shape=(self.latent_dim,))
+ label = Input(shape=(1,))
+ img = self.generator([noise, label])
+
+ # For the combined model we will only train the generator
+ self.discriminator.trainable = False
+
+ # The discriminator takes generated image as input and determines validity
+ # and the label of that image
+ valid = self.discriminator([img, label])
+
+ # The combined model (stacked generator and discriminator)
+ # Trains generator to fool discriminator
+ self.combined = Model([noise, label], valid)
+ self.combined.compile(loss=['binary_crossentropy'],
+ optimizer=optimizer)
+
+ def build_generator(self):
+
+ model = Sequential()
+
+ model.add(Dense(256, input_dim=self.latent_dim))
+ model.add(LeakyReLU(alpha=0.2))
+ model.add(BatchNormalization(momentum=0.8))
+ model.add(Dense(512))
+ model.add(LeakyReLU(alpha=0.2))
+ model.add(BatchNormalization(momentum=0.8))
+ model.add(Dense(1024))
+ model.add(LeakyReLU(alpha=0.2))
+ model.add(BatchNormalization(momentum=0.8))
+ model.add(Dense(np.prod(self.img_shape), activation='tanh'))
+ model.add(Reshape(self.img_shape))
+
+ #model.summary()
+
+ noise = Input(shape=(self.latent_dim,))
+ label = Input(shape=(1,), dtype='int32')
+ label_embedding = Flatten()(Embedding(self.num_classes, self.latent_dim)(label))
+
+ model_input = multiply([noise, label_embedding])
+ img = model(model_input)
+
+ return Model([noise, label], img)
+
+ def build_discriminator(self):
+
+ model = Sequential()
+
+ model.add(Dense(512, input_dim=np.prod(self.img_shape)))
+ model.add(LeakyReLU(alpha=0.2))
+ model.add(Dense(512))
+ model.add(LeakyReLU(alpha=0.2))
+ model.add(Dropout(0.4))
+ model.add(Dense(512))
+ model.add(LeakyReLU(alpha=0.2))
+ model.add(Dropout(0.4))
+ model.add(Dense(1, activation='sigmoid'))
+
+ #model.summary()
+
+ img = Input(shape=self.img_shape)
+ label = Input(shape=(1,), dtype='int32')
+
+ label_embedding = Flatten()(Embedding(self.num_classes, np.prod(self.img_shape))(label))
+ flat_img = Flatten()(img)
+
+ model_input = multiply([flat_img, label_embedding])
+
+ validity = model(model_input)
+
+ return Model([img, label], validity)
+
+ def train(self, epochs, batch_size=128, sample_interval=50, graph=False):
+
+ # Load the dataset
+ (X_train, y_train), (_, _) = mnist.load_data()
+
+ # Configure input
+ X_train = (X_train.astype(np.float32) - 127.5) / 127.5
+ X_train = np.expand_dims(X_train, axis=3)
+ y_train = y_train.reshape(-1, 1)
+
+ # Adversarial ground truths
+ valid = np.ones((batch_size, 1))
+ fake = np.zeros((batch_size, 1))
+
+ xaxis = np.arange(epochs)
+ loss = np.zeros((2,epochs))
+ for epoch in range(epochs):
+
+ # ---------------------
+ # Train Discriminator
+ # ---------------------
+
+ # Select a random half batch of images
+ idx = np.random.randint(0, X_train.shape[0], batch_size)
+ imgs, labels = X_train[idx], y_train[idx]
+
+ # Sample noise as generator input
+ noise = np.random.normal(0, 1, (batch_size, 100))
+
+ # Generate a half batch of new images
+ gen_imgs = self.generator.predict([noise, labels])
+
+ # Train the discriminator
+ d_loss_real = self.discriminator.train_on_batch([imgs, labels], valid)
+ d_loss_fake = self.discriminator.train_on_batch([gen_imgs, labels], fake)
+ d_loss = 0.5 * np.add(d_loss_real, d_loss_fake)
+
+ # ---------------------
+ # Train Generator
+ # ---------------------
+
+ # Condition on labels
+ sampled_labels = np.random.randint(0, 10, batch_size).reshape(-1, 1)
+ # Train the generator
+ g_loss = self.combined.train_on_batch([noise, sampled_labels], valid)
+
+ # Plot the progress
+ #print ("%d [D loss: %f, acc.: %.2f%%] [G loss: %f]" % (epoch, d_loss[0], 100*d_loss[1], g_loss))
+ if epoch % 500 == 0:
+ print(epoch)
+ loss[0][epoch] = d_loss[0]
+ loss[1][epoch] = g_loss
+
+ # If at save interval => save generated image samples
+ if epoch % sample_interval == 0:
+ self.sample_images(epoch)
+
+ if graph:
+ plt.plot(xaxis,loss[0])
+ plt.plot(xaxis,loss[1])
+ plt.legend(('Discriminator', 'Generator'), loc='best')
+ plt.xlabel('Epoch')
+ plt.ylabel('Binary Crossentropy Loss')
+
+ def sample_images(self, epoch):
+ r, c = 2, 5
+ noise = np.random.normal(0, 1, (r * c, 100))
+ sampled_labels = np.arange(0, 10).reshape(-1, 1)
+ dummy_labels = np.zeros(32).reshape(-1, 1)
+
+ gen_imgs = self.generator.predict([noise, dummy_labels])
+
+ # Rescale images 0 - 1
+ gen_imgs = 0.5 * gen_imgs + 0.5
+
+ fig, axs = plt.subplots(r, c)
+ cnt = 0
+ for i in range(r):
+ for j in range(c):
+ axs[i,j].imshow(gen_imgs[cnt,:,:,0], cmap='gray')
+ axs[i,j].set_title("Digit: %d" % sampled_labels[cnt])
+ axs[i,j].axis('off')
+ cnt += 1
+ fig.savefig("images/%d.png" % epoch)
+ plt.close()
+
+ def generate_data(self):
+ noise_train = np.random.normal(0, 1, (60000, 100))
+ noise_test = np.random.normal(0, 1, (10000, 100))
+
+ gen_train = np.zeros(60000).reshape(-1, 1)
+ gen_test = np.zeros(10000).reshape(-1, 1)
+ for i in range(10):
+ gen_train[i*600:] = i
+ gen_test[i*100:] = i
+
+ return self.generator.predict([noise_train, gen_train]), self.generator.predict([noise_test, gen_test]), gen_train, gen_test
+
+
+'''
+if __name__ == '__main__':
+ cgan = CGAN()
+ cgan.train(epochs=7000, batch_size=32, sample_interval=200)
+ train, test, tr_labels, te_labels = cgan.generate_data()
+ print(train.shape, test.shape)
+''' \ No newline at end of file