Ich habe ein GAN-Netzwerk. Der Generator zeichnet mnist Ziffern. Es funktioniert großartig. Aber ich kann nicht verstehen, wie es weiß, welche Ziffer es zeichnen sollte. Hier ist der Generator:CNN, GAN, Wie kann der Generator wissen, welche Klasse er zeichnen sollte?
def build_generator(latent_size):
# we will map a pair of (z, L), where z is a latent vector and L is a
# label drawn from P_c, to image space (..., 1, 28, 28)
cnn = Sequential()
cnn.add(Dense(1024, input_dim=latent_size, activation='relu'))
cnn.add(Dense(128 * 7 * 7, activation='relu'))
cnn.add(Reshape((128, 7, 7)))
# upsample to (..., 14, 14)
cnn.add(UpSampling2D(size=(2, 2)))
cnn.add(Conv2D(256, 5, padding='same',
activation='relu',
kernel_initializer='glorot_normal'))
# upsample to (..., 28, 28)
cnn.add(UpSampling2D(size=(2, 2)))
cnn.add(Conv2D(128, 5, padding='same',
activation='relu',
kernel_initializer='glorot_normal'))
# take a channel axis reduction
cnn.add(Conv2D(1, 2, padding='same',
activation='tanh',
kernel_initializer='glorot_normal'))
# this is the z space commonly refered to in GAN papers
latent = Input(shape=(latent_size,))
# this will be our label
image_class = Input(shape=(1,), dtype='int32')
cls = Flatten()(Embedding(num_classes, latent_size,
embeddings_initializer='glorot_normal')(image_class))
# hadamard product between z-space and a class conditional embedding
h = layers.multiply([latent, cls])
fake_image = cnn(h)
return Model([latent, image_class], fake_image)
Die Eingabe ist eine latent-Array
noise = np.random.uniform(-1, 1, (batch_size, latent_size))
und die Etiketten nur zufällig erzeugt.
Also meine Frage ist. Nachdem das Netzwerk die Labels eingebettet hat. Sie sollten wie folgt aussehen
So, jetzt. Wenn ich dem Netzwerk mehr Latenz-Arrays und Labels gebe. Er wird den latent-Arrays (das Rauschen) mit der Einbettung Multiplikation (der Etiketten): Also, was ich erwarte, ist:
Also das Netzwerk weiß, welche neue Array darstellt, welche Zahl.
aber die Ausgabe von np.multiply (Lärm, embedded_label) ist dies:
Wie kann das Netzwerk wissen, welche Ziffer sollte es ziehen?
######## EDIT:Also hier ist der ganze Code. Und es funktioniert. Aber warum? Die latent_size im Code ist 100. Die latent_size in meinen Bildern ist 2, weil ich sie visualisieren wollte. Aber ich denke, es ändert nichts, wenn ich das Rauschen im 2-dimensionalen Raum oder im 100-dimensionalen Raum multipliziere. Am Ende liegen die neuen Punkte mit dem Label "1" nicht nahe bei den anderen Punkten mit dem Label "1". Das Gleiche gilt für die anderen Ziffern ("0", "1", "2", "3", ...)
#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Train an Auxiliary Classifier Generative Adversarial Network (ACGAN) on the
MNIST dataset. See https://arxiv.org/abs/1610.09585 for more details.
You should start to see reasonable images after ~5 epochs, and good images
by ~15 epochs. You should use a GPU, as the convolution-heavy operations are
very slow on the CPU. Prefer the TensorFlow backend if you plan on iterating,
as the compilation time can be a blocker using Theano.
Timings:
Hardware | Backend | Time/Epoch
-------------------------------------------
CPU | TF | 3 hrs
Titan X (maxwell) | TF | 4 min
Titan X (maxwell) | TH | 7 min
Consult https://github.com/lukedeo/keras-acgan for more information and
example output
"""
from __future__ import print_function
from collections import defaultdict
try:
import cPickle as pickle
except ImportError:
import pickle
from PIL import Image
from six.moves import range
import keras.backend as K
from keras.datasets import mnist
from keras import layers
from keras.layers import Input, Dense, Reshape, Flatten, Embedding, Dropout
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
from keras.utils.generic_utils import Progbar
import numpy as np
import time, os
np.random.seed(1337)
K.set_image_data_format('channels_first')
num_classes = 10
def build_generator(latent_size):
# we will map a pair of (z, L), where z is a latent vector and L is a
# label drawn from P_c, to image space (..., 1, 28, 28)
cnn = Sequential()
cnn.add(Dense(1024, input_dim=latent_size, activation='relu'))
cnn.add(Dense(128 * 7 * 7, activation='relu'))
cnn.add(Reshape((128, 7, 7)))
# upsample to (..., 14, 14)
cnn.add(UpSampling2D(size=(2, 2)))
cnn.add(Conv2D(256, 5, padding='same',
activation='relu',
kernel_initializer='glorot_normal'))
# upsample to (..., 28, 28)
cnn.add(UpSampling2D(size=(2, 2)))
cnn.add(Conv2D(128, 5, padding='same',
activation='relu',
kernel_initializer='glorot_normal'))
# take a channel axis reduction
cnn.add(Conv2D(1, 2, padding='same',
activation='tanh',
kernel_initializer='glorot_normal'))
# this is the z space commonly refered to in GAN papers
latent = Input(shape=(latent_size,))
# this will be our label
image_class = Input(shape=(1,), dtype='int32')
cls = Flatten()(Embedding(num_classes, latent_size,
embeddings_initializer='glorot_normal')(image_class))
# hadamard product between z-space and a class conditional embedding
h = layers.multiply([latent, cls])
fake_image = cnn(h)
return Model([latent, image_class], fake_image)
def build_discriminator():
# build a relatively standard conv net, with LeakyReLUs as suggested in
# the reference paper
cnn = Sequential()
cnn.add(Conv2D(32, 3, padding='same', strides=2,
input_shape=(1, 28, 28)))
cnn.add(LeakyReLU())
cnn.add(Dropout(0.3))
cnn.add(Conv2D(64, 3, padding='same', strides=1))
cnn.add(LeakyReLU())
cnn.add(Dropout(0.3))
cnn.add(Conv2D(128, 3, padding='same', strides=2))
cnn.add(LeakyReLU())
cnn.add(Dropout(0.3))
cnn.add(Conv2D(256, 3, padding='same', strides=1))
cnn.add(LeakyReLU())
cnn.add(Dropout(0.3))
cnn.add(Flatten())
image = Input(shape=(1, 28, 28))
features = cnn(image)
# first output (name=generation) is whether or not the discriminator
# thinks the image that is being shown is fake, and the second output
# (name=auxiliary) is the class that the discriminator thinks the image
# belongs to.
fake = Dense(1, activation='sigmoid', name='generation')(features) # fake oder nicht fake
aux = Dense(num_classes, activation='softmax', name='auxiliary')(features) #welche klasse ist es
return Model(image, [fake, aux])
if __name__ == '__main__':
start_time_string = time.strftime("%Y_%m_%d_%H_%M_%S", time.gmtime())
os.mkdir('history/' + start_time_string)
os.mkdir('images/' + start_time_string)
os.mkdir('acgan/' + start_time_string)
# batch and latent size taken from the paper
epochs = 50
batch_size = 100
latent_size = 100
# Adam parameters suggested in https://arxiv.org/abs/1511.06434
adam_lr = 0.00005
adam_beta_1 = 0.5
# build the discriminator
discriminator = build_discriminator()
discriminator.compile(
optimizer=Adam(lr=adam_lr, beta_1=adam_beta_1),
loss=['binary_crossentropy', 'sparse_categorical_crossentropy']
)
# build the generator
generator = build_generator(latent_size)
generator.compile(optimizer=Adam(lr=adam_lr, beta_1=adam_beta_1),
loss='binary_crossentropy')
latent = Input(shape=(latent_size,))
image_class = Input(shape=(1,), dtype='int32')
# get a fake image
fake = generator([latent, image_class])
# we only want to be able to train generation for the combined model
discriminator.trainable = False
fake, aux = discriminator(fake)
combined = Model([latent, image_class], [fake, aux])
combined.compile(
optimizer=Adam(lr=adam_lr, beta_1=adam_beta_1),
loss=['binary_crossentropy', 'sparse_categorical_crossentropy']
)
# get our mnist data, and force it to be of shape (..., 1, 28, 28) with
# range [-1, 1]
(x_train, y_train), (x_test, y_test) = mnist.load_data()
x_train = (x_train.astype(np.float32) - 127.5)/127.5
x_train = np.expand_dims(x_train, axis=1)
x_test = (x_test.astype(np.float32) - 127.5)/127.5
x_test = np.expand_dims(x_test, axis=1)
num_train, num_test = x_train.shape[0], x_test.shape[0]
train_history = defaultdict(list)
test_history = defaultdict(list)
for epoch in range(1, epochs + 1):
print('Epoch {}/{}'.format(epoch, epochs))
num_batches = int(x_train.shape[0]/batch_size)
progress_bar = Progbar(target=num_batches)
epoch_gen_loss = []
epoch_disc_loss = []
for index in range(num_batches):
# generate a new batch of noise
noise = np.random.uniform(-1, 1, (batch_size, latent_size))
# get a batch of real images
image_batch = x_train[index * batch_size:(index + 1) * batch_size]
label_batch = y_train[index * batch_size:(index + 1) * batch_size]
# sample some labels from p_c
sampled_labels = np.random.randint(0, num_classes, batch_size)
# generate a batch of fake images, using the generated labels as a
# conditioner. We reshape the sampled labels to be
# (batch_size, 1) so that we can feed them into the embedding
# layer as a length one sequence
generated_images = generator.predict(
[noise, sampled_labels.reshape((-1, 1))], verbose=0)
x = np.concatenate((image_batch, generated_images))
y = np.array([1] * batch_size + [0] * batch_size)
aux_y = np.concatenate((label_batch, sampled_labels), axis=0)
# see if the discriminator can figure itself out...
epoch_disc_loss.append(discriminator.train_on_batch(x, [y, aux_y]))
# make new noise. we generate 2 * batch size here such that we have
# the generator optimize over an identical number of images as the
# discriminator
noise = np.random.uniform(-1, 1, (2 * batch_size, latent_size))
sampled_labels = np.random.randint(0, num_classes, 2 * batch_size)
# we want to train the generator to trick the discriminator
# For the generator, we want all the {fake, not-fake} labels to say
# not-fake
trick = np.ones(2 * batch_size)
epoch_gen_loss.append(combined.train_on_batch(
[noise, sampled_labels.reshape((-1, 1))],
[trick, sampled_labels]))
progress_bar.update(index + 1)
print('Testing for epoch {}:'.format(epoch))
# evaluate the testing loss here
# generate a new batch of noise
noise = np.random.uniform(-1, 1, (num_test, latent_size))
# sample some labels from p_c and generate images from them
sampled_labels = np.random.randint(0, num_classes, num_test)
generated_images = generator.predict(
[noise, sampled_labels.reshape((-1, 1))], verbose=False)
x = np.concatenate((x_test, generated_images))
y = np.array([1] * num_test + [0] * num_test)
aux_y = np.concatenate((y_test, sampled_labels), axis=0)
# see if the discriminator can figure itself out...
discriminator_test_loss = discriminator.evaluate(
x, [y, aux_y], verbose=False)
discriminator_train_loss = np.mean(np.array(epoch_disc_loss), axis=0)
# make new noise
noise = np.random.uniform(-1, 1, (2 * num_test, latent_size))
sampled_labels = np.random.randint(0, num_classes, 2 * num_test)
trick = np.ones(2 * num_test)
generator_test_loss = combined.evaluate(
[noise, sampled_labels.reshape((-1, 1))],
[trick, sampled_labels], verbose=False)
generator_train_loss = np.mean(np.array(epoch_gen_loss), axis=0)
# generate an epoch report on performance
train_history['generator'].append(generator_train_loss)
train_history['discriminator'].append(discriminator_train_loss)
test_history['generator'].append(generator_test_loss)
test_history['discriminator'].append(discriminator_test_loss)
print('{0:<22s} | {1:4s} | {2:15s} | {3:5s}'.format(
'component', *discriminator.metrics_names))
print('-' * 65)
ROW_FMT = '{0:<22s} | {1:<4.2f} | {2:<15.2f} | {3:<5.2f}'
print(ROW_FMT.format('generator (train)',
*train_history['generator'][-1]))
print(ROW_FMT.format('generator (test)',
*test_history['generator'][-1]))
print(ROW_FMT.format('discriminator (train)',
*train_history['discriminator'][-1]))
print(ROW_FMT.format('discriminator (test)',
*test_history['discriminator'][-1]))
# save weights every epoch
generator.save_weights(
'acgan/'+ start_time_string +'/params_generator_epoch_{0:03d}.hdf5'.format(epoch), True)
discriminator.save_weights(
'acgan/'+ start_time_string +'/params_discriminator_epoch_{0:03d}.hdf5'.format(epoch), True)
# generate some digits to display
noise = np.random.uniform(-1, 1, (100, latent_size))
sampled_labels = np.array([
[i] * num_classes for i in range(num_classes)
]).reshape(-1, 1)
# get a batch to display
generated_images = generator.predict(
[noise, sampled_labels], verbose=0)
# arrange them into a grid
img = (np.concatenate([r.reshape(-1, 28)
for r in np.split(generated_images, num_classes)
], axis=-1) * 127.5 + 127.5).astype(np.uint8)
Image.fromarray(img).save(
'images/'+ start_time_string +'/plot_epoch_{0:03d}_generated.png'.format(epoch))
pickle.dump({'train': train_history, 'test': test_history},
open('history/'+ start_time_string +'/acgan-history.pkl', 'wb'))
Was ist der Wert von "latent_size"? –
Also, im Code für die Ziffernzeichnung mit dem GAN. Es ist 100. Aber in den Bildern ist es 2, weil ich es visualisieren möchte. – tag