17 CGAN和ACGAN(下)
ACGAN
再透過一張圖瞭解ACGAN(Auxiliary Classifier GAN)的原理
和CGAN不同的是,
不直接輸入
。
不僅需要判斷每個樣本的真假,還需要完成一個分類任務即預測
,透過增加一個輔助分類器實現
對
而言,損失函式如下
對
而言,損失函式如下
還是以CelebA的Male作為條件,在WGAN的基礎上實現ACGAN
載入庫
# -*- coding: utf-8 -*-
import tensorflow as tf
import numpy as np
import os
import matplotlib。pyplot as plt
%matplotlib inline
from imageio import imread, imsave, mimsave
import cv2
import glob
from tqdm import tqdm
載入圖片
images = glob。glob(‘celeba/*。jpg’)
print(len(images))
讀取圖片的Male標籤
tags = {}
target = ‘Male’
with open(‘list_attr_celeba。txt’, ‘r’) as fr:
lines = fr。readlines()
all_tags = lines[0]。strip(‘\n’)。split()
for i in range(1, len(lines)):
line = lines[i]。strip(‘\n’)。split()
if int(line[all_tags。index(target) + 1]) == 1:
tags[line[0]] = [1, 0] # 男
else:
tags[line[0]] = [0, 1] # 女
print(len(tags))
print(all_tags)
定義一些常量、網路輸入、輔助函式
batch_size = 100
z_dim = 100
WIDTH = 64
HEIGHT = 64
LABEL = 2
LAMBDA = 10
DIS_ITERS = 3 # 5
OUTPUT_DIR = ‘samples’
if not os。path。exists(OUTPUT_DIR):
os。mkdir(OUTPUT_DIR)
X = tf。placeholder(dtype=tf。float32, shape=[batch_size, HEIGHT, WIDTH, 3], name=‘X’)
Y = tf。placeholder(dtype=tf。float32, shape=[batch_size, LABEL], name=‘Y’)
noise = tf。placeholder(dtype=tf。float32, shape=[batch_size, z_dim], name=‘noise’)
is_training = tf。placeholder(dtype=tf。bool, name=‘is_training’)
def lrelu(x, leak=0。2):
return tf。maximum(x, leak * x)
判別器部分,去掉條件輸入,增加分類輸出
def discriminator(image, reuse=None, is_training=is_training):
momentum = 0。9
with tf。variable_scope(‘discriminator’, reuse=reuse):
h0 = lrelu(tf。layers。conv2d(image, kernel_size=5, filters=64, strides=2, padding=‘same’))
h1 = lrelu(tf。layers。conv2d(h0, kernel_size=5, filters=128, strides=2, padding=‘same’))
h2 = lrelu(tf。layers。conv2d(h1, kernel_size=5, filters=256, strides=2, padding=‘same’))
h3 = lrelu(tf。layers。conv2d(h2, kernel_size=5, filters=512, strides=2, padding=‘same’))
h4 = tf。contrib。layers。flatten(h3)
Y_ = tf。layers。dense(h4, units=LABEL)
h4 = tf。layers。dense(h4, units=1)
return h4, Y_
生成器部分,沒有任何改動
def generator(z, label, is_training=is_training):
momentum = 0。9
with tf。variable_scope(‘generator’, reuse=None):
d = 4
z = tf。concat([z, label], axis=1)
h0 = tf。layers。dense(z, units=d * d * 512)
h0 = tf。reshape(h0, shape=[-1, d, d, 512])
h0 = tf。nn。relu(tf。contrib。layers。batch_norm(h0, is_training=is_training, decay=momentum))
h1 = tf。layers。conv2d_transpose(h0, kernel_size=5, filters=256, strides=2, padding=‘same’)
h1 = tf。nn。relu(tf。contrib。layers。batch_norm(h1, is_training=is_training, decay=momentum))
h2 = tf。layers。conv2d_transpose(h1, kernel_size=5, filters=128, strides=2, padding=‘same’)
h2 = tf。nn。relu(tf。contrib。layers。batch_norm(h2, is_training=is_training, decay=momentum))
h3 = tf。layers。conv2d_transpose(h2, kernel_size=5, filters=64, strides=2, padding=‘same’)
h3 = tf。nn。relu(tf。contrib。layers。batch_norm(h3, is_training=is_training, decay=momentum))
h4 = tf。layers。conv2d_transpose(h3, kernel_size=5, filters=3, strides=2, padding=‘same’, activation=tf。nn。tanh, name=‘g’)
return h4
定義損失函式,加上分類部分對應的損失。理論上分類問題應該用交叉熵作為損失函式,這裡使用MSE效果也不錯
g = generator(noise, Y)
d_real, y_real = discriminator(X)
d_fake, y_fake = discriminator(g, reuse=True)
loss_d_real = -tf。reduce_mean(d_real)
loss_d_fake = tf。reduce_mean(d_fake)
loss_cls_real = tf。losses。mean_squared_error(Y, y_real)
loss_cls_fake = tf。losses。mean_squared_error(Y, y_fake)
loss_d = loss_d_real + loss_d_fake + loss_cls_real
loss_g = -tf。reduce_mean(d_fake) + loss_cls_fake
alpha = tf。random_uniform(shape=[batch_size, 1, 1, 1], minval=0。, maxval=1。)
interpolates = alpha * X + (1 - alpha) * g
grad = tf。gradients(discriminator(interpolates, reuse=True), [interpolates])[0]
slop = tf。sqrt(tf。reduce_sum(tf。square(grad), axis=[1]))
gp = tf。reduce_mean((slop - 1。) ** 2)
loss_d += LAMBDA * gp
vars_g = [var for var in tf。trainable_variables() if var。name。startswith(‘generator’)]
vars_d = [var for var in tf。trainable_variables() if var。name。startswith(‘discriminator’)]
定義最佳化器
update_ops = tf。get_collection(tf。GraphKeys。UPDATE_OPS)
with tf。control_dependencies(update_ops):
optimizer_d = tf。train。AdamOptimizer(learning_rate=0。0002, beta1=0。5)。minimize(loss_d, var_list=vars_d)
optimizer_g = tf。train。AdamOptimizer(learning_rate=0。0002, beta1=0。5)。minimize(loss_g, var_list=vars_g)
拼接圖片的函式
def montage(images):
if isinstance(images, list):
images = np。array(images)
img_h = images。shape[1]
img_w = images。shape[2]
n_plots = int(np。ceil(np。sqrt(images。shape[0])))
if len(images。shape) == 4 and images。shape[3] == 3:
m = np。ones(
(images。shape[1] * n_plots + n_plots + 1,
images。shape[2] * n_plots + n_plots + 1, 3)) * 0。5
elif len(images。shape) == 4 and images。shape[3] == 1:
m = np。ones(
(images。shape[1] * n_plots + n_plots + 1,
images。shape[2] * n_plots + n_plots + 1, 1)) * 0。5
elif len(images。shape) == 3:
m = np。ones(
(images。shape[1] * n_plots + n_plots + 1,
images。shape[2] * n_plots + n_plots + 1)) * 0。5
else:
raise ValueError(‘Could not parse image shape of {}’。format(images。shape))
for i in range(n_plots):
for j in range(n_plots):
this_filter = i * n_plots + j
if this_filter < images。shape[0]:
this_img = images[this_filter]
m[1 + i + i * img_h:1 + i + (i + 1) * img_h,
1 + j + j * img_w:1 + j + (j + 1) * img_w] = this_img
return m
整理資料
X_all = []
Y_all = []
for i in tqdm(range(len(images))):
image = imread(images[i])
h = image。shape[0]
w = image。shape[1]
if h > w:
image = image[h // 2 - w // 2: h // 2 + w // 2, :, :]
else:
image = image[:, w // 2 - h // 2: w // 2 + h // 2, :]
image = cv2。resize(image, (WIDTH, HEIGHT))
image = (image / 255。 - 0。5) * 2
X_all。append(image)
image_name = images[i][images[i]。find(‘/’) + 1:]
Y_all。append(tags[image_name])
X_all = np。array(X_all)
Y_all = np。array(Y_all)
print(X_all。shape, Y_all。shape)
檢視資料樣例
for i in range(10):
plt。imshow((X_all[i, :, :, :] + 1) / 2)
plt。show()
print(Y_all[i, :])
定義隨機產生批資料的函式
def get_random_batch():
data_index = np。arange(X_all。shape[0])
np。random。shuffle(data_index)
data_index = data_index[:batch_size]
X_batch = X_all[data_index, :, :, :]
Y_batch = Y_all[data_index, :]
return X_batch, Y_batch
訓練模型,根據ACGAN作相應調整
sess = tf。Session()
sess。run(tf。global_variables_initializer())
zs = np。random。uniform(-1。0, 1。0, [batch_size // 2, z_dim])。astype(np。float32)
z_samples = []
y_samples = []
for i in range(batch_size // 2):
z_samples。append(zs[i, :])
y_samples。append([1, 0])
z_samples。append(zs[i, :])
y_samples。append([0, 1])
samples = []
loss = {‘d’: [], ‘g’: []}
for i in tqdm(range(60000)):
for j in range(DIS_ITERS):
n = np。random。uniform(-1。0, 1。0, [batch_size, z_dim])。astype(np。float32)
X_batch, Y_batch = get_random_batch()
_, d_ls = sess。run([optimizer_d, loss_d], feed_dict={X: X_batch, Y: Y_batch, noise: n, is_training: True})
_, g_ls = sess。run([optimizer_g, loss_g], feed_dict={X: X_batch, Y: Y_batch, noise: n, is_training: True})
loss[‘d’]。append(d_ls)
loss[‘g’]。append(g_ls)
if i % 500 == 0:
print(i, d_ls, g_ls)
gen_imgs = sess。run(g, feed_dict={noise: z_samples, Y: y_samples, is_training: False})
gen_imgs = (gen_imgs + 1) / 2
imgs = [img[:, :, :] for img in gen_imgs]
gen_imgs = montage(imgs)
plt。axis(‘off’)
plt。imshow(gen_imgs)
imsave(os。path。join(OUTPUT_DIR, ‘sample_%d。jpg’ % i), gen_imgs)
plt。show()
samples。append(gen_imgs)
plt。plot(loss[‘d’], label=‘Discriminator’)
plt。plot(loss[‘g’], label=‘Generator’)
plt。legend(loc=‘upper right’)
plt。savefig(‘Loss。png’)
plt。show()
mimsave(os。path。join(OUTPUT_DIR, ‘samples。gif’), samples, fps=10)
結果如下,比CGAN的結果好一些,崩掉的情況比較少,而且人臉更真實更清晰
儲存模型
saver = tf。train。Saver()
saver。save(sess, ‘。/celeba_acgan’, global_step=60000)
在單機上載入模型,進行以下兩個嘗試:
固定噪音,漸變條件;
固定條件,漸變噪音。
# -*- coding: utf-8 -*-
import tensorflow as tf
import numpy as np
import matplotlib。pyplot as plt
batch_size = 100
z_dim = 100
LABEL = 2
def montage(images):
if isinstance(images, list):
images = np。array(images)
img_h = images。shape[1]
img_w = images。shape[2]
n_plots = int(np。ceil(np。sqrt(images。shape[0])))
if len(images。shape) == 4 and images。shape[3] == 3:
m = np。ones(
(images。shape[1] * n_plots + n_plots + 1,
images。shape[2] * n_plots + n_plots + 1, 3)) * 0。5
elif len(images。shape) == 4 and images。shape[3] == 1:
m = np。ones(
(images。shape[1] * n_plots + n_plots + 1,
images。shape[2] * n_plots + n_plots + 1, 1)) * 0。5
elif len(images。shape) == 3:
m = np。ones(
(images。shape[1] * n_plots + n_plots + 1,
images。shape[2] * n_plots + n_plots + 1)) * 0。5
else:
raise ValueError(‘Could not parse image shape of {}’。format(images。shape))
for i in range(n_plots):
for j in range(n_plots):
this_filter = i * n_plots + j
if this_filter < images。shape[0]:
this_img = images[this_filter]
m[1 + i + i * img_h:1 + i + (i + 1) * img_h,
1 + j + j * img_w:1 + j + (j + 1) * img_w] = this_img
return m
sess = tf。Session()
sess。run(tf。global_variables_initializer())
saver = tf。train。import_meta_graph(‘。/celeba_acgan-60000。meta’)
saver。restore(sess, tf。train。latest_checkpoint(‘。/’))
graph = tf。get_default_graph()
g = graph。get_tensor_by_name(‘generator/g/Tanh:0’)
noise = graph。get_tensor_by_name(‘noise:0’)
Y = graph。get_tensor_by_name(‘Y:0’)
is_training = graph。get_tensor_by_name(‘is_training:0’)
# 固定噪音,漸變條件
n = np。random。uniform(-1。0, 1。0, [10, z_dim])。astype(np。float32)
ns = []
y_samples = []
for i in range(100):
ns。append(n[i // 10, :])
y_samples。append([i % 10 / 9, 1 - i % 10 / 9])
gen_imgs = sess。run(g, feed_dict={noise: ns, Y: y_samples, is_training: False})
gen_imgs = (gen_imgs + 1) / 2
imgs = [img[:, :, :] for img in gen_imgs]
gen_imgs = montage(imgs)
gen_imgs = np。clip(gen_imgs, 0, 1)
plt。figure(figsize=(8, 8))
plt。axis(‘off’)
plt。imshow(gen_imgs)
plt。show()
# 固定條件,漸變噪音
n = np。random。uniform(-1。0, 1。0, [5, 2, z_dim])。astype(np。float32)
ns = []
y_samples = []
for i in range(5):
for k in range(2):
for j in range(10):
start = n[i, 0, :]
end = n[i, 1, :]
ns。append(start + j * (end - start) / 9)
if k == 0:
y_samples。append([0, 1])
else:
y_samples。append([1, 0])
gen_imgs = sess。run(g, feed_dict={noise: ns, Y: y_samples, is_training: False})
gen_imgs = (gen_imgs + 1) / 2
imgs = [img[:, :, :] for img in gen_imgs]
gen_imgs = montage(imgs)
gen_imgs = np。clip(gen_imgs, 0, 1)
plt。figure(figsize=(8, 8))
plt。axis(‘off’)
plt。imshow(gen_imgs)
plt。show()
由女變男的過程
人臉兩兩之間的漸變
參考
Conditional Generative Adversarial Nets:
https://
arxiv。org/abs/1411。1784
Conditional Image Synthesis With Auxiliary Classifier GANs:
https://
arxiv。org/abs/1610。0958
5
影片講解課程