MNIST数据集
tensorflow1.9.0版本
python3.7
spyder IDE
整个项目只需要两个脚本文件,一个存放数据集的文件夹,一个存放结果的文件夹。名称如下图所示:
首先将下载好的数据集放置在MNIST_data文件夹下,你下载的数据集应该是4个压缩包。具体如下图所示:
然后,编写数据导入脚本,这里只需要导入一些相关的库。from __future__ import absolute_import from __future__ import division from __future__ import print_functionimport gzip import os import tempfileimport numpy from six.moves import urllib from six.moves import xrange import tensorflow as tf from tensorflow.contrib.learn.python.learn.datasets.mnist import read_data_sets
最后就是模型构建和训练的代码了。代码中相关语句的作用注释的很清楚,如有疑问,欢迎交流。import numpy as np import tensorflow as tf #import pickle import matplotlib.pyplot as plt import input_data import matplotlib.image as mgmnist = input_data.read_data_sets('MNIST_data', one_hot=True)def get_inputs(noise_dim, image_height, image_width, image_depth): ''' :param noise_dim: 噪声图片的size :param image_height: 真实图像的height :param image_width: 真实图像的width :param image_depth: 真实图像的depth ''' inputs_real = tf.placeholder(tf.float32, [None, image_height, image_width, image_depth], name='inputs_real') inputs_noise = tf.placeholder(tf.float32, [None, noise_dim], name='inputs_noise') return inputs_real, inputs_noisedef get_generator(noise_img, output_dim, is_train=True, alpha=0.01): ''' :param noise_img: 噪声信号,tensor类型 :param output_dim: 生成图片的depth :param is_train: 是否为训练状态,该参数主要用于作为batch_normalization方法中的参数使用 :param alpha: Leaky ReLU系数 ''' with tf.variable_scope('generator', reuse=tf.AUTO_REUSE): # 100 x 1 to 4 x 4 x 512 # 全连接层 layer1 = tf.layers.dense(noise_img, 4*4*512) layer1 = tf.reshape(layer1, [-1, 4, 4, 512]) # batch normalization layer1 = tf.layers.batch_normalization(layer1, training=is_train) # Leaky ReLU layer1 = tf.maximum(alpha * layer1, layer1) # dropout layer1 = tf.nn.dropout(layer1, keep_prob=0.8) # 4 x 4 x 512 to 7 x 7 x 256 layer2 = tf.layers.conv2d_transpose(layer1, 256, 4, strides=1, padding='valid') layer2 = tf.layers.batch_normalization(layer2, training=is_train) layer2 = tf.maximum(alpha * layer2, layer2) layer2 = tf.nn.dropout(layer2, keep_prob=0.8) # 7 x 7 256 to 14 x 14 x 128 layer3 = tf.layers.conv2d_transpose(layer2, 128, 3, strides=2, padding='same') layer3 = tf.layers.batch_normalization(layer3, training=is_train) layer3 = tf.maximum(alpha * layer3, layer3) layer3 = tf.nn.dropout(layer3, keep_prob=0.8) # 14 x 14 x 128 to 28 x 28 x 1 logits = tf.layers.conv2d_transpose(layer3, output_dim, 3, strides=2, padding='same') # MNIST原始数据集的像素范围在0-1,这里的生成图片范围为(-1,1) # 因此在训练时,记住要把MNIST像素范围进行resize outputs = tf.tanh(logits) return outputsdef get_discriminator(inputs_img, alpha=0.01): ''' @param inputs_img: 输入图片,tensor类型 @param alpha: Leaky ReLU系数 ''' with tf.variable_scope('discriminator', reuse=tf.AUTO_REUSE): # 28 x 28 x 1 to 14 x 14 x 128 # 第一层不加入BN layer1 = tf.layers.conv2d(inputs_img, 128, 3, strides=2, padding='same') layer1 = tf.maximum(alpha * layer1, layer1) layer1 = tf.nn.dropout(layer1, keep_prob=0.8) # 14 x 14 x 128 to 7 x 7 x 256 layer2 = tf.layers.conv2d(layer1, 256, 3, strides=2, padding='same') layer2 = tf.layers.batch_normalization(layer2, training=True) layer2 = tf.maximum(alpha * layer2, layer2) layer2 = tf.nn.dropout(layer2, keep_prob=0.8) # 7 x 7 x 256 to 4 x 4 x 512 layer3 = tf.layers.conv2d(layer2, 512, 3, strides=2, padding='same') layer3 = tf.layers.batch_normalization(layer3, training=True) layer3 = tf.maximum(alpha * layer3, layer3) layer3 = tf.nn.dropout(layer3, keep_prob=0.8) # 4 x 4 x 512 to 4*4*512 x 1 flatten = tf.reshape(layer3, (-1, 4*4*512)) logits = tf.layers.dense(flatten, 1) outputs = tf.sigmoid(logits) return logits, outputsdef get_loss(inputs_real, inputs_noise, image_depth, smooth=0.1): ''' @param inputs_real: 输入图片,tensor类型 @param inputs_noise: 噪声图片,tensor类型 @param image_depth: 图片的depth(或者叫channel) @param smooth: label smoothing的参数 ''' g_outputs = get_generator(inputs_noise, image_depth, is_train=True) d_logits_real, d_outputs_real = get_discriminator(inputs_real) d_logits_fake, d_outputs_fake = get_discriminator(g_outputs) # 计算Loss g_loss = tf.reduce_mean(tf.nn.sigmoid_cross_entropy_with_logits(logits=d_logits_fake, labels=tf.ones_like(d_outputs_fake)*(1-smooth))) d_loss_real = tf.reduce_mean(tf.nn.sigmoid_cross_entropy_with_logits(logits=d_logits_real, labels=tf.ones_like(d_outputs_real)*(1-smooth))) d_loss_fake = tf.reduce_mean(tf.nn.sigmoid_cross_entropy_with_logits(logits=d_logits_fake, labels=tf.zeros_like(d_outputs_fake))) d_loss = tf.add(d_loss_real, d_loss_fake) return g_loss, d_lossdef get_optimizer(g_loss, d_loss, beta1=0.9, learning_rate=0.001): ''' @param g_loss: Generator的Loss @param d_loss: Discriminator的Loss @learning_rate: 学习率 ''' train_vars = tf.trainable_variables() g_vars = [var for var in train_vars if var.name.startswith('generator')] d_vars = [var for var in train_vars if var.name.startswith('discriminator')] # Optimizer with tf.control_dependencies(tf.get_collection(tf.GraphKeys.UPDATE_OPS)): g_opt = tf.train.AdamOptimizer(learning_rate, beta1=beta1).minimize(g_loss, var_list=g_vars) d_opt = tf.train.AdamOptimizer(learning_rate, beta1=beta1).minimize(d_loss, var_list=d_vars) return g_opt, d_optdef plot_images(samples): fig, axes = plt.subplots(nrows=1, ncols=1, sharex=True, sharey=True, figsize=(1,1)) for img, ax in zip(samples, axes): ax.imshow(img.reshape((28, 28)), cmap='Greys_r') ax.get_xaxis().set_visible(False) ax.get_yaxis().set_visible(False) fig.tight_layout(pad=0)def save_as_img(samples, path,step): ''' 此函数用于保存每次训练完成后的结果图,用于查看训练效果 @param samples: 用于保存的数据集合 @param path:保存文件路径 ''' for img in samples: mg.imsave(path+str(step)+'.jpeg', img.reshape((28,28)), cmap='Greys_r') def show_generator_output(sess, n_images, inputs_noise, output_dim): ''' 此函数用于生成效果图 @param sess: TensorFlow session @param n_images: 展示图片的数量 @param inputs_noise: 噪声图片 @param output_dim: 图片的depth(或者叫channel) @param image_mode: 图像模式:RGB或者灰度 ''' #cmap = 'Greys_r' noise_shape = inputs_noise.get_shape().as_list()[-1] # 生成噪声图片 examples_noise = np.random.uniform(-1, 1, size=[n_images, noise_shape]) samples = sess.run(get_generator(inputs_noise, output_dim, False), feed_dict={inputs_noise: examples_noise}) result = np.squeeze(samples, -1) #删除单一维度的条目 return result#Train # 定义参数 batch_size = 64 noise_size = 100 epochs = 20 n_samples = 10 learning_rate = 0.001 beta1 = 0.9 path = 'result/'def train(noise_size, data_shape, batch_size, n_samples): ''' @param noise_size: 噪声size @param data_shape: 真实图像shape @batch_size: @n_samples: 显示示例图片数量 ''' # 存储loss losses = [] steps = 0 inputs_real, inputs_noise = get_inputs(noise_size, data_shape[1], data_shape[2], data_shape[3]) g_loss, d_loss = get_loss(inputs_real, inputs_noise, data_shape[-1]) g_train_opt, d_train_opt = get_optimizer(g_loss, d_loss, beta1, learning_rate) with tf.Session() as sess: sess.run(tf.global_variables_initializer()) # 迭代epoch for e in range(epochs): for batch_i in range(mnist.train.num_examples//batch_size): steps += 1 batch = mnist.train.next_batch(batch_size) batch_images = batch[0].reshape((batch_size, data_shape[1], data_shape[2], data_shape[3])) # scale to -1, 1 batch_images = batch_images * 2 - 1 # noise batch_noise = np.random.uniform(-1, 1, size=(batch_size, noise_size)) # run optimizer _ = sess.run(g_train_opt, feed_dict={inputs_real: batch_images, inputs_noise: batch_noise}) _ = sess.run(d_train_opt, feed_dict={inputs_real: batch_images, inputs_noise: batch_noise}) if steps % 50 == 0: train_loss_d = d_loss.eval({inputs_real: batch_images, inputs_noise: batch_noise}) train_loss_g = g_loss.eval({inputs_real: batch_images, inputs_noise: batch_noise}) losses.append((train_loss_d, train_loss_g)) # 显示图片 samples = show_generator_output(sess, n_samples, inputs_noise, data_shape[-1]) #plot_images(samples) #保存结果图 save_as_img(np.array(samples), path, steps) print('Epoch {}/{}....'.format(e+1, epochs), 'Discriminator Loss: {:.4f}....'.format(train_loss_d), 'Generator Loss: {:.4f}....'. format(train_loss_g))with tf.Graph().as_default(): train(noise_size, [-1, 28, 28, 1], batch_size, n_samples)
此项目适用于刚刚入门GAN网络的童鞋,文中可能存在不足的地方,敬请指正。