python验证码识别训练模型生产_利用Tensorflow构建和训练自己的CNN来做简单的验证码识别方式...

Tensorflow是目前最流行的深度学习框架，我们可以用它来搭建自己的卷积神经网络并训练自己的分类器，本文介绍怎样使用Tensorflow构建自己的CNN，怎样训练用于简单的验证码识别的分类器。本文假设你已经安装好了Tensorflow，了解过CNN的一些知识。

下面将分步介绍怎样获得训练数据，怎样使用tensorflow构建卷积神经网络，怎样训练，以及怎样测试训练出来的分类器

1. 准备训练样本

使用Python的库captcha来生成我们需要的训练样本，代码如下：

import sys

import os

import shutil

import random

import time

#captcha是用于生成验证码图片的库，可以 pip install captcha 来安装它

from captcha.image import ImageCaptcha

#用于生成验证码的字符集

CHAR_SET = ['0','1','2','3','4','5','6','7','8','9']

#字符集的长度

CHAR_SET_LEN = 10

#验证码的长度，每个验证码由4个数字组成

CAPTCHA_LEN = 4

#验证码图片的存放路径

CAPTCHA_IMAGE_PATH = 'E:/Tensorflow/captcha/images/'

#用于模型测试的验证码图片的存放路径，它里面的验证码图片作为测试集

TEST_IMAGE_PATH = 'E:/Tensorflow/captcha/test/'

#用于模型测试的验证码图片的个数，从生成的验证码图片中取出来放入测试集中

TEST_IMAGE_NUMBER = 50

#生成验证码图片，4位的十进制数字可以有10000种验证码

def generate_captcha_image(charSet = CHAR_SET, charSetLen=CHAR_SET_LEN, captchaImgPath=CAPTCHA_IMAGE_PATH):

k = 0

total = 1

for i in range(CAPTCHA_LEN):

total *= charSetLen

for i in range(charSetLen):

for j in range(charSetLen):

for m in range(charSetLen):

for n in range(charSetLen):

captcha_text = charSet[i] + charSet[j] + charSet[m] + charSet[n]

image = ImageCaptcha()

image.write(captcha_text, captchaImgPath + captcha_text + '.jpg')

k += 1

sys.stdout.write("rCreating %d/%d" % (k, total))

sys.stdout.flush()

#从验证码的图片集中取出一部分作为测试集，这些图片不参加训练，只用于模型的测试

def prepare_test_set():

fileNameList = []

for filePath in os.listdir(CAPTCHA_IMAGE_PATH):

captcha_name = filePath.split('/')[-1]

fileNameList.append(captcha_name)

random.seed(time.time())

random.shuffle(fileNameList)

for i in range(TEST_IMAGE_NUMBER):

name = fileNameList[i]

shutil.move(CAPTCHA_IMAGE_PATH + name, TEST_IMAGE_PATH + name)

if __name__ == '__main__':

generate_captcha_image(CHAR_SET, CHAR_SET_LEN, CAPTCHA_IMAGE_PATH)

prepare_test_set()

sys.stdout.write("nFinished")

sys.stdout.flush()

运行上面的代码，可以生成验证码图片，

生成的验证码图片如下图所示：

2. 构建CNN，训练分类器

代码如下：

import tensorflow as tf

import numpy as np

from PIL import Image

import os

import random

import time

#验证码图片的存放路径

CAPTCHA_IMAGE_PATH = 'E:/Tensorflow/captcha/images/'

#验证码图片的宽度

CAPTCHA_IMAGE_WIDHT = 160

#验证码图片的高度

CAPTCHA_IMAGE_HEIGHT = 60

CHAR_SET_LEN = 10

CAPTCHA_LEN = 4

#60%的验证码图片放入训练集中

TRAIN_IMAGE_PERCENT = 0.6

#训练集，用于训练的验证码图片的文件名

TRAINING_IMAGE_NAME = []

#验证集，用于模型验证的验证码图片的文件名

VALIDATION_IMAGE_NAME = []

#存放训练好的模型的路径

MODEL_SAVE_PATH = 'E:/Tensorflow/captcha/models/'

def get_image_file_name(imgPath=CAPTCHA_IMAGE_PATH):

fileName = []

total = 0

for filePath in os.listdir(imgPath):

captcha_name = filePath.split('/')[-1]

fileName.append(captcha_name)

total += 1

return fileName, total

#将验证码转换为训练时用的标签向量，维数是 40

#例如，如果验证码是 ‘0296' ，则对应的标签是

# [1 0 0 0 0 0 0 0 0 0

# 0 0 1 0 0 0 0 0 0 0

# 0 0 0 0 0 0 0 0 0 1

# 0 0 0 0 0 0 1 0 0 0]

def name2label(name):

label = np.zeros(CAPTCHA_LEN * CHAR_SET_LEN)

for i, c in enumerate(name):

idx = i*CHAR_SET_LEN + ord(c) - ord('0')

label[idx] = 1

return label

#取得验证码图片的数据以及它的标签

def get_data_and_label(fileName, filePath=CAPTCHA_IMAGE_PATH):

pathName = os.path.join(filePath, fileName)

img = Image.open(pathName)

#转为灰度图

img = img.convert("L")

image_array = np.array(img)

image_data = image_array.flatten()/255

image_label = name2label(fileName[0:CAPTCHA_LEN])

return image_data, image_label

#生成一个训练batch

def get_next_batch(batchSize=32, trainOrTest='train', step=0):

batch_data = np.zeros([batchSize, CAPTCHA_IMAGE_WIDHT*CAPTCHA_IMAGE_HEIGHT])

batch_label = np.zeros([batchSize, CAPTCHA_LEN * CHAR_SET_LEN])

fileNameList = TRAINING_IMAGE_NAME

if trainOrTest == 'validate':

fileNameList = VALIDATION_IMAGE_NAME

totalNumber = len(fileNameList)

indexStart = step*batchSize

for i in range(batchSize):

index = (i + indexStart) % totalNumber

name = fileNameList[index]

img_data, img_label = get_data_and_label(name)

batch_data[i, : ] = img_data

batch_label[i, : ] = img_label

return batch_data, batch_label

#构建卷积神经网络并训练

def train_data_with_CNN():

#初始化权值

def weight_variable(shape, name='weight'):

init = tf.truncated_normal(shape, stddev=0.1)

var = tf.Variable(initial_value=init, name=name)

return var

#初始化偏置

def bias_variable(shape, name='bias'):

init = tf.constant(0.1, shape=shape)

var = tf.Variable(init, name=name)

return var

#卷积

def conv2d(x, W, name='conv2d'):

return tf.nn.conv2d(x, W, strides=[1,1,1,1], padding='SAME', name=name)

#池化

def max_pool_2X2(x, name='maxpool'):

return tf.nn.max_pool(x, ksize=[1,2,2,1], strides=[1,2,2,1], padding='SAME', name=name)

#输入层

#请注意 X 的 name，在测试model时会用到它

X = tf.placeholder(tf.float32, [None, CAPTCHA_IMAGE_WIDHT * CAPTCHA_IMAGE_HEIGHT], name='data-input')

Y = tf.placeholder(tf.float32, [None, CAPTCHA_LEN * CHAR_SET_LEN], name='label-input')

x_input = tf.reshape(X, [-1, CAPTCHA_IMAGE_HEIGHT, CAPTCHA_IMAGE_WIDHT, 1], name='x-input')

#dropout,防止过拟合

#请注意 keep_prob 的 name，在测试model时会用到它

keep_prob = tf.placeholder(tf.float32, name='keep-prob')

#第一层卷积

W_conv1 = weight_variable([5,5,1,32], 'W_conv1')

B_conv1 = bias_variable([32], 'B_conv1')

conv1 = tf.nn.relu(conv2d(x_input, W_conv1, 'conv1') + B_conv1)

conv1 = max_pool_2X2(conv1, 'conv1-pool')

conv1 = tf.nn.dropout(conv1, keep_prob)

#第二层卷积

W_conv2 = weight_variable([5,5,32,64], 'W_conv2')

B_conv2 = bias_variable([64], 'B_conv2')

conv2 = tf.nn.relu(conv2d(conv1, W_conv2,'conv2') + B_conv2)

conv2 = max_pool_2X2(conv2, 'conv2-pool')

conv2 = tf.nn.dropout(conv2, keep_prob)

#第三层卷积

W_conv3 = weight_variable([5,5,64,64], 'W_conv3')

B_conv3 = bias_variable([64], 'B_conv3')

conv3 = tf.nn.relu(conv2d(conv2, W_conv3, 'conv3') + B_conv3)

conv3 = max_pool_2X2(conv3, 'conv3-pool')

conv3 = tf.nn.dropout(conv3, keep_prob)

#全链接层

#每次池化后，图片的宽度和高度均缩小为原来的一半，进过上面的三次池化，宽度和高度均缩小8倍

W_fc1 = weight_variable([20*8*64, 1024], 'W_fc1')

B_fc1 = bias_variable([1024], 'B_fc1')

fc1 = tf.reshape(conv3, [-1, 20*8*64])

fc1 = tf.nn.relu(tf.add(tf.matmul(fc1, W_fc1), B_fc1))

fc1 = tf.nn.dropout(fc1, keep_prob)

#输出层

W_fc2 = weight_variable([1024, CAPTCHA_LEN * CHAR_SET_LEN], 'W_fc2')

B_fc2 = bias_variable([CAPTCHA_LEN * CHAR_SET_LEN], 'B_fc2')

output = tf.add(tf.matmul(fc1, W_fc2), B_fc2, 'output')

loss = tf.reduce_mean(tf.nn.sigmoid_cross_entropy_with_logits(labels=Y, logits=output))

optimizer = tf.train.AdamOptimizer(0.001).minimize(loss)

predict = tf.reshape(output, [-1, CAPTCHA_LEN, CHAR_SET_LEN], name='predict')

labels = tf.reshape(Y, [-1, CAPTCHA_LEN, CHAR_SET_LEN], name='labels')

#预测结果

#请注意 predict_max_idx 的 name，在测试model时会用到它

predict_max_idx = tf.argmax(predict, axis=2, name='predict_max_idx')

labels_max_idx = tf.argmax(labels, axis=2, name='labels_max_idx')

predict_correct_vec = tf.equal(predict_max_idx, labels_max_idx)

accuracy = tf.reduce_mean(tf.cast(predict_correct_vec, tf.float32))

saver = tf.train.Saver()

with tf.Session() as sess:

sess.run(tf.global_variables_initializer())

steps = 0

for epoch in range(6000):

train_data, train_label = get_next_batch(64, 'train', steps)

sess.run(optimizer, feed_dict={X : train_data, Y : train_label, keep_prob:0.75})

if steps % 100 == 0:

test_data, test_label = get_next_batch(100, 'validate', steps)

acc = sess.run(accuracy, feed_dict={X : test_data, Y : test_label, keep_prob:1.0})

print("steps=%d, accuracy=%f" % (steps, acc))

if acc > 0.99:

saver.save(sess, MODEL_SAVE_PATH+"crack_captcha.model", global_step=steps)

break

steps += 1

if __name__ == '__main__':

image_filename_list, total = get_image_file_name(CAPTCHA_IMAGE_PATH)

random.seed(time.time())

#打乱顺序

random.shuffle(image_filename_list)

trainImageNumber = int(total * TRAIN_IMAGE_PERCENT)

#分成测试集

TRAINING_IMAGE_NAME = image_filename_list[ : trainImageNumber]

#和验证集

VALIDATION_IMAGE_NAME = image_filename_list[trainImageNumber : ]

train_data_with_CNN()

print('Training finished')

运行上面的代码，开始训练，训练要花些时间，如果没有GPU的话，会慢些，

训练完后，输出如下结果，经过4100次的迭代，训练出来的分类器模型在验证集上识别的准确率为99.5%

生成的模型文件如下，在模型测试时将用到这些文件

3. 测试模型

编写代码，对训练出来的模型进行测试

import tensorflow as tf

import numpy as np

from PIL import Image

import os

import matplotlib.pyplot as plt

CAPTCHA_LEN = 4

MODEL_SAVE_PATH = 'E:/Tensorflow/captcha/models/'

TEST_IMAGE_PATH = 'E:/Tensorflow/captcha/test/'

def get_image_data_and_name(fileName, filePath=TEST_IMAGE_PATH):

pathName = os.path.join(filePath, fileName)

img = Image.open(pathName)

#转为灰度图

img = img.convert("L")

image_array = np.array(img)

image_data = image_array.flatten()/255

image_name = fileName[0:CAPTCHA_LEN]

return image_data, image_name

def digitalStr2Array(digitalStr):

digitalList = []

for c in digitalStr:

digitalList.append(ord(c) - ord('0'))

return np.array(digitalList)

def model_test():

nameList = []

for pathName in os.listdir(TEST_IMAGE_PATH):

nameList.append(pathName.split('/')[-1])

totalNumber = len(nameList)

#加载graph

saver = tf.train.import_meta_graph(MODEL_SAVE_PATH+"crack_captcha.model-4100.meta")

graph = tf.get_default_graph()

#从graph取得 tensor，他们的name是在构建graph时定义的(查看上面第2步里的代码)

input_holder = graph.get_tensor_by_name("data-input:0")

keep_prob_holder = graph.get_tensor_by_name("keep-prob:0")

predict_max_idx = graph.get_tensor_by_name("predict_max_idx:0")

with tf.Session() as sess:

saver.restore(sess, tf.train.latest_checkpoint(MODEL_SAVE_PATH))

count = 0

for fileName in nameList:

img_data, img_name = get_image_data_and_name(fileName, TEST_IMAGE_PATH)

predict = sess.run(predict_max_idx, feed_dict={input_holder:[img_data], keep_prob_holder : 1.0})

filePathName = TEST_IMAGE_PATH + fileName

print(filePathName)

img = Image.open(filePathName)

plt.imshow(img)

plt.axis('off')

plt.show()

predictValue = np.squeeze(predict)

rightValue = digitalStr2Array(img_name)

if np.array_equal(predictValue, rightValue):

result = '正确'

count += 1

else:

result = '错误'

print('实际值：{}， 预测值：{}，测试结果：{}'.format(rightValue, predictValue, result))

print('n')

print('正确率：%.2f%%(%d/%d)' % (count*100/totalNumber, count, totalNumber))

if __name__ == '__main__':

model_test()

对模型的测试结果如下，在测试集上识别的准确率为 94%

下面是两个识别错误的验证码

以上这篇利用Tensorflow构建和训练自己的CNN来做简单的验证码识别方式就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持脚本之家。