GAN 生成mnist数据

 参考资料

GAN原理学习笔记

生成式对抗网络GAN汇总

GAN的理解与TensorFlow的实现

TensorFlow小试牛刀(2):GAN生成手写数字

参考代码之一

#coding=utf-8
#http://blog.csdn.net/u012223913/article/details/75051516?locationNum=1&fps=1
import tensorflow as tf
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec
import os
from tensorflow.examples.tutorials.mnist import input_data

sess = tf.InteractiveSession()

mb_size = 128
Z_dim = 100

mnist = input_data.read_data_sets('MNIST_data', one_hot=True)

def weight_var(shape, name):
    return tf.get_variable(name=name, shape=shape, initializer=tf.contrib.layers.xavier_initializer())


def bias_var(shape, name):
    return tf.get_variable(name=name, shape=shape, initializer=tf.constant_initializer(0))


# discriminater net

X = tf.placeholder(tf.float32, shape=[None, 784], name='X')

# X [128 784] z1 = W * x + b  # 矩阵乘法 128 * 784 * 784 * 128 = [128 128] D_W1 = weight_var([784, 128], 'D_W1') D_b1 = bias_var([128], 'D_b1') #z2 = W * z1 + b # 矩阵乘法 128 * 128 * 128 * 1 = [128 1] 输出判决结果，二分类 D_W2 = weight_var([128, 1], 'D_W2') D_b2 = bias_var([1], 'D_b2') 

theta_D = [D_W1, D_W2, D_b1, D_b2]


# generator net

Z = tf.placeholder(tf.float32, shape=[None, 100], name='Z')

# z [128 784] z1 = W * x + b  # 矩阵乘法 128 * 100 * 100 * 128 = [128 128]
G_W1 = weight_var([100, 128], 'G_W1') G_b1 = bias_var([128], 'G_B1') #z2 = W * z1 + b # 矩阵乘法 128 * 128 * 128 * 784 = [128 784] 输出28*28的图像
G_W2 = weight_var([128, 784], 'G_W2') G_b2 = bias_var([784], 'G_B2')

theta_G = [G_W1, G_W2, G_b1, G_b2]

def generator(z):
    G_h1 = tf.nn.relu(tf.matmul(z, G_W1) + G_b1)
    G_log_prob = tf.matmul(G_h1, G_W2) + G_b2
    G_prob = tf.nn.sigmoid(G_log_prob)

    return G_prob


def discriminator(x):
    D_h1 = tf.nn.relu(tf.matmul(x, D_W1) + D_b1)
    D_logit = tf.matmul(D_h1, D_W2) + D_b2
    D_prob = tf.nn.sigmoid(D_logit)
    return D_prob, D_logit

G_sample = generator(Z)
D_real, D_logit_real = discriminator(X)
D_fake, D_logit_fake = discriminator(G_sample)


#discriminator输出为1表示ground truth #discriminator输出为0表示非ground truth #对于生成网络希望两点： #(2)希望D_real尽可能大，这样保证正确识别真正的样本 #(1)希望D_fake尽可能小，这样可以剔除假的生成样本
D_loss = -tf.reduce_mean(tf.log(D_real) + tf.log(1. - D_fake)) #对于判别网络, 希望D_fake尽可能大，这样可以迷惑生成网络，
G_loss = -tf.reduce_mean(tf.log(D_fake))

D_optimizer = tf.train.AdamOptimizer().minimize(D_loss, var_list=theta_D)
G_optimizer = tf.train.AdamOptimizer().minimize(G_loss, var_list=theta_G)

init = tf.initialize_all_variables()
saver = tf.train.Saver()
# 启动默认图
sess = tf.Session()
# 初始化
sess.run(init)

def sample_Z(m, n):
    '''Uniform prior for G(Z)'''
    return np.random.uniform(-1., 1., size=[m, n])


def plot(samples):
    fig = plt.figure(figsize=(4, 4))
    gs = gridspec.GridSpec(4, 4)
    gs.update(wspace=0.05, hspace=0.05)

    for i, sample in enumerate(samples):  # [i,samples[i]] imax=16
        ax = plt.subplot(gs[i])
        plt.axis('off')
        ax.set_xticklabels([])
        ax.set_aspect('equal')
        plt.imshow(sample.reshape(28, 28), cmap='Greys_r')

    return fig

if not os.path.exists('out/'):
    os.makedirs('out/')

i = 0

for it in range(1000000):
    if it % 1000 == 0:
        samples = sess.run(G_sample, feed_dict={
                           Z: sample_Z(16, Z_dim)})  # 16*784
        fig = plot(samples)
        plt.savefig('out/{}.png'.format(str(i).zfill(3)), bbox_inches='tight')
        i += 1
        plt.close(fig)

    X_mb, _ = mnist.train.next_batch(mb_size)#ground truth

    _, D_loss_curr = sess.run([D_optimizer, D_loss], feed_dict={
                              X: X_mb, Z: sample_Z(mb_size, Z_dim)})
    _, G_loss_curr = sess.run([G_optimizer, G_loss], feed_dict={
                              Z: sample_Z(mb_size, Z_dim)})

    if it % 1000 == 0:
        print('Iter: {}'.format(it))
        print('D loss: {:.4}'.format(D_loss_curr))
        print('G_loss: {:.4}'.format(G_loss_curr))
        print()

参考代码之二

#http://blog.csdn.net/sparkexpert/article/details/70147409

import tensorflow as tf
from tensorflow.examples.tutorials.mnist import input_data
import numpy as np
#from skimage.io import imsave
import scipy
import os
import shutil

img_height = 28
img_width = 28
img_size = img_height * img_width

to_train = True
to_restore = False
output_path = "output"

# 总迭代次数500
max_epoch = 500

h1_size = 150
h2_size = 300
z_size = 100
batch_size = 256


# generate (model 1)
def build_generator(z_prior):
    w1 = tf.Variable(tf.truncated_normal([z_size, h1_size], stddev=0.1), name="g_w1", dtype=tf.float32)
    b1 = tf.Variable(tf.zeros([h1_size]), name="g_b1", dtype=tf.float32)
    h1 = tf.nn.relu(tf.matmul(z_prior, w1) + b1)
    w2 = tf.Variable(tf.truncated_normal([h1_size, h2_size], stddev=0.1), name="g_w2", dtype=tf.float32)
    b2 = tf.Variable(tf.zeros([h2_size]), name="g_b2", dtype=tf.float32)
    h2 = tf.nn.relu(tf.matmul(h1, w2) + b2)
    w3 = tf.Variable(tf.truncated_normal([h2_size, img_size], stddev=0.1), name="g_w3", dtype=tf.float32)
    b3 = tf.Variable(tf.zeros([img_size]), name="g_b3", dtype=tf.float32)
    h3 = tf.matmul(h2, w3) + b3
    x_generate = tf.nn.tanh(h3)
    g_params = [w1, b1, w2, b2, w3, b3]
    return x_generate, g_params


# discriminator (model 2)
def build_discriminator(x_data, x_generated, keep_prob):
    # tf.concat
    x_in = tf.concat([x_data, x_generated], 0)
    w1 = tf.Variable(tf.truncated_normal([img_size, h2_size], stddev=0.1), name="d_w1", dtype=tf.float32)
    b1 = tf.Variable(tf.zeros([h2_size]), name="d_b1", dtype=tf.float32)
    h1 = tf.nn.dropout(tf.nn.relu(tf.matmul(x_in, w1) + b1), keep_prob)
    w2 = tf.Variable(tf.truncated_normal([h2_size, h1_size], stddev=0.1), name="d_w2", dtype=tf.float32)
    b2 = tf.Variable(tf.zeros([h1_size]), name="d_b2", dtype=tf.float32)
    h2 = tf.nn.dropout(tf.nn.relu(tf.matmul(h1, w2) + b2), keep_prob)
    w3 = tf.Variable(tf.truncated_normal([h1_size, 1], stddev=0.1), name="d_w3", dtype=tf.float32)
    b3 = tf.Variable(tf.zeros([1]), name="d_b3", dtype=tf.float32)
    h3 = tf.matmul(h2, w3) + b3
    y_data = tf.nn.sigmoid(tf.slice(h3, [0, 0], [batch_size, -1], name=None))
    y_generated = tf.nn.sigmoid(tf.slice(h3, [batch_size, 0], [-1, -1], name=None))
    d_params = [w1, b1, w2, b2, w3, b3]
    return y_data, y_generated, d_params


#
def show_result(batch_res, fname, grid_size=(8, 8), grid_pad=5):
    batch_res = 0.5 * batch_res.reshape((batch_res.shape[0], img_height, img_width)) + 0.5
    img_h, img_w = batch_res.shape[1], batch_res.shape[2]
    grid_h = img_h * grid_size[0] + grid_pad * (grid_size[0] - 1)
    grid_w = img_w * grid_size[1] + grid_pad * (grid_size[1] - 1)
    img_grid = np.zeros((grid_h, grid_w), dtype=np.uint8)
    for i, res in enumerate(batch_res):
        if i >= grid_size[0] * grid_size[1]:
            break
        img = (res) * 255
        img = img.astype(np.uint8)
        row = (i // grid_size[0]) * (img_h + grid_pad)
        col = (i % grid_size[1]) * (img_w + grid_pad)
        img_grid[row:row + img_h, col:col + img_w] = img
    #imsave(fname, img_grid)
    #img.save('output/num.jpg')
    scipy.misc.imsave(fname, img_grid)


def train():
    # load data（mnist手写数据集）
    mnist = input_data.read_data_sets('mnist_data', one_hot=True)

    x_data = tf.placeholder(tf.float32, [batch_size, img_size], name="x_data")
    z_prior = tf.placeholder(tf.float32, [batch_size, z_size], name="z_prior")
    keep_prob = tf.placeholder(tf.float32, name="keep_prob")
    global_step = tf.Variable(0, name="global_step", trainable=False)

    # 创建生成模型
    x_generated, g_params = build_generator(z_prior)
    # 创建判别模型
    y_data, y_generated, d_params = build_discriminator(x_data, x_generated, keep_prob)

    # 损失函数的设置
    d_loss = - (tf.log(y_data) + tf.log(1 - y_generated))
    g_loss = - tf.log(y_generated)

    optimizer = tf.train.AdamOptimizer(0.0001)

    # 两个模型的优化函数
    d_trainer = optimizer.minimize(d_loss, var_list=d_params)
    g_trainer = optimizer.minimize(g_loss, var_list=g_params)

    init = tf.initialize_all_variables()

    saver = tf.train.Saver()
    # 启动默认图
    sess = tf.Session()
    # 初始化
    sess.run(init)

    if to_restore:
        chkpt_fname = tf.train.latest_checkpoint(output_path)
        saver.restore(sess, chkpt_fname)
    else:
        if os.path.exists(output_path):
            shutil.rmtree(output_path)
        os.mkdir(output_path)

    z_sample_val = np.random.normal(0, 1, size=(batch_size, z_size)).astype(np.float32)

    steps = 60000 / batch_size
    for i in range(sess.run(global_step), max_epoch):
        for j in np.arange(steps):
            #         for j in range(steps):
            print("epoch:%s, iter:%s" % (i, j))
            # 每一步迭代，我们都会加载256个训练样本，然后执行一次train_step
            x_value, _ = mnist.train.next_batch(batch_size)
            x_value = 2 * x_value.astype(np.float32) - 1
            z_value = np.random.normal(0, 1, size=(batch_size, z_size)).astype(np.float32)
            # 执行生成
            sess.run(d_trainer,
                     feed_dict={x_data: x_value, z_prior: z_value, keep_prob: np.sum(0.7).astype(np.float32)})
            # 执行判别
            if j % 1 == 0:
                sess.run(g_trainer,
                         feed_dict={x_data: x_value, z_prior: z_value, keep_prob: np.sum(0.7).astype(np.float32)})
        x_gen_val = sess.run(x_generated, feed_dict={z_prior: z_sample_val})
        show_result(x_gen_val, "output/sample{0}.jpg".format(i))
        z_random_sample_val = np.random.normal(0, 1, size=(batch_size, z_size)).astype(np.float32)
        x_gen_val = sess.run(x_generated, feed_dict={z_prior: z_random_sample_val})
        show_result(x_gen_val, "output/random_sample{0}.jpg".format(i))
        sess.run(tf.assign(global_step, i + 1))
        saver.save(sess, os.path.join(output_path, "model"), global_step=global_step)


def test():
    z_prior = tf.placeholder(tf.float32, [batch_size, z_size], name="z_prior")
    x_generated, _ = build_generator(z_prior)
    chkpt_fname = tf.train.latest_checkpoint(output_path)

    init = tf.initialize_all_variables()
    sess = tf.Session()
    saver = tf.train.Saver()
    sess.run(init)
    saver.restore(sess, chkpt_fname)
    z_test_value = np.random.normal(0, 1, size=(batch_size, z_size)).astype(np.float32)
    x_gen_val = sess.run(x_generated, feed_dict={z_prior: z_test_value})
    show_result(x_gen_val, "output/test_result.jpg")


if __name__ == '__main__':
    if to_train:
        train()
    else:
        test()