TF- 驗(yàn)證碼生成與識別

驗(yàn)證碼生成

# coding: utf-8

# 驗(yàn)證碼生成庫
from captcha.image import ImageCaptcha  # pip install captcha
import random
import sys
import os
os.environ['TF_CPP_MIN_LOG_LEVEL'] = '2'
number = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']

# alphabet = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']
# ALPHABET = ['A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z']

def random_captcha_text(char_set=number, captcha_size=4):
    # 驗(yàn)證碼列表(驗(yàn)證碼長度為4位,captcha_size=4)
    captcha_text = []
    for i in range(captcha_size):
        # 隨機(jī)選擇
        c = random.choice(char_set)
        # 加入驗(yàn)證碼列表
        captcha_text.append(c)
    return captcha_text


# 生成字符對應(yīng)的驗(yàn)證碼
def gen_captcha_text_and_image():
    image = ImageCaptcha()
    # 獲得隨機(jī)生成的驗(yàn)證碼
    captcha_text = random_captcha_text()
    # 把驗(yàn)證碼列表轉(zhuǎn)為字符串
    captcha_text = ''.join(captcha_text)
    # 生成驗(yàn)證碼
    captcha = image.generate(captcha_text)
    image.write(captcha_text, 'captcha/images/' + captcha_text + '.jpg')  # 寫到文件


# 數(shù)量少于10000,因?yàn)橹孛?num = 10000
if __name__ == '__main__':
    for i in range(num):
        gen_captcha_text_and_image()
        sys.stdout.write('\r>> Creating image %d/%d' % (i + 1, num))
        sys.stdout.flush()
    sys.stdout.write('\n')
    sys.stdout.flush()

    print("生成完畢")

生成結(jié)果:


四位隨機(jī)數(shù)字驗(yàn)證碼

生成tfrecord 文件

# coding: utf-8

import tensorflow as tf
import os
import random
import sys
from PIL import Image
import numpy as np


# 驗(yàn)證集數(shù)量
_NUM_TEST = 500

# 隨機(jī)種子
_RANDOM_SEED = 0

# 數(shù)據(jù)集路徑
DATASET_DIR = "captcha/images/"

# tfrecord文件存放路徑
TFRECORD_DIR = "captcha/"


# 判斷tfrecord文件是否存在
def _dataset_exists(dataset_dir):
    for split_name in ['train', 'test']:
        output_filename = os.path.join(dataset_dir, split_name + '.tfrecords')
        if not tf.gfile.Exists(output_filename):
            return False
    return True


# 獲取所有驗(yàn)證碼圖片
def _get_filenames_and_classes(dataset_dir):
    photo_filenames = []
    for filename in os.listdir(dataset_dir):
        # 獲取文件路徑
        path = os.path.join(dataset_dir, filename)
        photo_filenames.append(path)
    return photo_filenames


def int64_feature(values):
    if not isinstance(values, (tuple, list)):
        values = [values]
    return tf.train.Feature(int64_list=tf.train.Int64List(value=values))


def bytes_feature(values):
    return tf.train.Feature(bytes_list=tf.train.BytesList(value=[values]))


def image_to_tfexample(image_data, label0, label1, label2, label3):
    # Abstract base class for protocol messages.
    return tf.train.Example(features=tf.train.Features(feature={
        'image': bytes_feature(image_data),
        'label0': int64_feature(label0),
        'label1': int64_feature(label1),
        'label2': int64_feature(label2),
        'label3': int64_feature(label3),
    }))


# 把數(shù)據(jù)轉(zhuǎn)為TFRecord格式
def _convert_dataset(split_name, filenames, dataset_dir):
    assert split_name in ['train', 'test']

    with tf.Session() as sess:
        # 定義tfrecord文件的路徑+名字
        output_filename = os.path.join(TFRECORD_DIR, split_name + '.tfrecords')
        with tf.python_io.TFRecordWriter(output_filename) as tfrecord_writer:
            for i, filename in enumerate(filenames):
                try:
                    sys.stdout.write('\r>> Converting image %d/%d' % (i + 1, len(filenames)))
                    sys.stdout.flush()

                    # 讀取圖片
                    image_data = Image.open(filename)
                    # 根據(jù)模型的結(jié)構(gòu)resize
                    image_data = image_data.resize((224, 224))
                    # 灰度化
                    image_data = np.array(image_data.convert('L'))
                    # 將圖片轉(zhuǎn)化為bytes
                    image_data = image_data.tobytes()

                    # 獲取label
                    labels = filename.split('/')[-1][0:4]
                    num_labels = []
                    for j in range(4):
                        num_labels.append(int(labels[j]))

                    # 生成protocol數(shù)據(jù)類型
                    example = image_to_tfexample(image_data, num_labels[0], num_labels[1], num_labels[2], num_labels[3])
                    tfrecord_writer.write(example.SerializeToString())

                except IOError as e:
                    print('Could not read:', filename)
                    print('Error:', e)
                    print('Skip it\n')
    sys.stdout.write('\n')
    sys.stdout.flush()


# 判斷tfrecord文件是否存在
if _dataset_exists(TFRECORD_DIR):
    print('tfcecord文件已存在')

else:
    # 獲得所有圖片
    photo_filenames = _get_filenames_and_classes(DATASET_DIR)

    # 把數(shù)據(jù)切分為訓(xùn)練集和測試集,并打亂
    random.seed(_RANDOM_SEED)
    random.shuffle(photo_filenames)
    training_filenames = photo_filenames[_NUM_TEST:]
    testing_filenames = photo_filenames[:_NUM_TEST]

    # 數(shù)據(jù)轉(zhuǎn)換
    _convert_dataset('train', training_filenames, DATASET_DIR)
    _convert_dataset('test', testing_filenames, DATASET_DIR)

    print('生成tfcecord文件')

生成的tfrecord文件

驗(yàn)證碼識別的兩種方式

  • 把標(biāo)簽轉(zhuǎn)為向量,向量長度為40。比如有一個(gè)驗(yàn)證碼為0782,



    它的標(biāo)簽可以轉(zhuǎn)為長度為40的向量:1000000000 0000000100 0000000010 0010000000
    訓(xùn)練方法跟0-9手寫數(shù)字識別類似。

  • 使用多任務(wù)學(xué)習(xí)的方式

拆分為4個(gè)標(biāo)簽,比如有一個(gè)驗(yàn)證碼為0782

Label0:1000000000
Label1:0000000100
Label2:0000000010
Label3:0010000000

多任務(wù)學(xué)習(xí)一般有兩種方式:

1 .Multi-task Learning - 交替訓(xùn)練

適用于不同的任務(wù)有不同的訓(xùn)練集

2 .Multi-task Learning – 聯(lián)合訓(xùn)練

適用于不同的任務(wù)有相同的數(shù)據(jù)集

訓(xùn)練

nets

# coding: utf-8


import tensorflow as tf
from nets import nets_factory



# 不同字符數(shù)量
CHAR_SET_LEN = 10
# 圖片高度
IMAGE_HEIGHT = 60
# 圖片寬度
IMAGE_WIDTH = 160
# 批次
BATCH_SIZE = 25
# tfrecord文件存放路徑
TFRECORD_FILE = "captcha/train.tfrecords"

# placeholder
x = tf.placeholder(tf.float32, [None, 224, 224])
y0 = tf.placeholder(tf.float32, [None])
y1 = tf.placeholder(tf.float32, [None])
y2 = tf.placeholder(tf.float32, [None])
y3 = tf.placeholder(tf.float32, [None])

# 學(xué)習(xí)率
lr = tf.Variable(0.003, dtype=tf.float32)


# 從tfrecord讀出數(shù)據(jù)
def read_and_decode(filename):
    # 根據(jù)文件名生成一個(gè)隊(duì)列
    filename_queue = tf.train.string_input_producer([filename])
    reader = tf.TFRecordReader()
    # 返回文件名和文件
    _, serialized_example = reader.read(filename_queue)
    features = tf.parse_single_example(serialized_example,
                                       features={
                                           'image': tf.FixedLenFeature([], tf.string),
                                           'label0': tf.FixedLenFeature([], tf.int64),
                                           'label1': tf.FixedLenFeature([], tf.int64),
                                           'label2': tf.FixedLenFeature([], tf.int64),
                                           'label3': tf.FixedLenFeature([], tf.int64),
                                       })
    # 獲取圖片數(shù)據(jù)
    image = tf.decode_raw(features['image'], tf.uint8)
    # tf.train.shuffle_batch必須確定shape
    image = tf.reshape(image, [224, 224])
    # 圖片預(yù)處理
    image = tf.cast(image, tf.float32) / 255.0
    image = tf.subtract(image, 0.5)
    image = tf.multiply(image, 2.0)
    # 獲取label
    label0 = tf.cast(features['label0'], tf.int32)
    label1 = tf.cast(features['label1'], tf.int32)
    label2 = tf.cast(features['label2'], tf.int32)
    label3 = tf.cast(features['label3'], tf.int32)

    return image, label0, label1, label2, label3


# 獲取圖片數(shù)據(jù)和標(biāo)簽
image, label0, label1, label2, label3 = read_and_decode(TFRECORD_FILE)

# 使用shuffle_batch可以隨機(jī)打亂
image_batch, label_batch0, label_batch1, label_batch2, label_batch3 = tf.train.shuffle_batch(
    [image, label0, label1, label2, label3], batch_size=BATCH_SIZE,
    capacity=50000, min_after_dequeue=10000, num_threads=1)

# 定義網(wǎng)絡(luò)結(jié)構(gòu)
train_network_fn = nets_factory.get_network_fn(
    'alexnet_v2',
    num_classes=CHAR_SET_LEN,
    weight_decay=0.0005,
    is_training=True)

with tf.Session() as sess:
    # inputs: a tensor of size [batch_size, height, width, channels]
    X = tf.reshape(x, [BATCH_SIZE, 224, 224, 1])
    # 數(shù)據(jù)輸入網(wǎng)絡(luò)得到輸出值
    logits0, logits1, logits2, logits3, end_points = train_network_fn(X)

    # 把標(biāo)簽轉(zhuǎn)成one_hot的形式
    one_hot_labels0 = tf.one_hot(indices=tf.cast(y0, tf.int32), depth=CHAR_SET_LEN)
    one_hot_labels1 = tf.one_hot(indices=tf.cast(y1, tf.int32), depth=CHAR_SET_LEN)
    one_hot_labels2 = tf.one_hot(indices=tf.cast(y2, tf.int32), depth=CHAR_SET_LEN)
    one_hot_labels3 = tf.one_hot(indices=tf.cast(y3, tf.int32), depth=CHAR_SET_LEN)

    # 計(jì)算loss
    loss0 = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(logits=logits0, labels=one_hot_labels0))
    loss1 = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(logits=logits1, labels=one_hot_labels1))
    loss2 = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(logits=logits2, labels=one_hot_labels2))
    loss3 = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(logits=logits3, labels=one_hot_labels3))
    # 計(jì)算總的loss
    total_loss = (loss0 + loss1 + loss2 + loss3) / 4.0
    # 優(yōu)化total_loss
    optimizer = tf.train.AdamOptimizer(learning_rate=lr).minimize(total_loss)

    # 計(jì)算準(zhǔn)確率
    correct_prediction0 = tf.equal(tf.argmax(one_hot_labels0, 1), tf.argmax(logits0, 1))
    accuracy0 = tf.reduce_mean(tf.cast(correct_prediction0, tf.float32))

    correct_prediction1 = tf.equal(tf.argmax(one_hot_labels1, 1), tf.argmax(logits1, 1))
    accuracy1 = tf.reduce_mean(tf.cast(correct_prediction1, tf.float32))

    correct_prediction2 = tf.equal(tf.argmax(one_hot_labels2, 1), tf.argmax(logits2, 1))
    accuracy2 = tf.reduce_mean(tf.cast(correct_prediction2, tf.float32))

    correct_prediction3 = tf.equal(tf.argmax(one_hot_labels3, 1), tf.argmax(logits3, 1))
    accuracy3 = tf.reduce_mean(tf.cast(correct_prediction3, tf.float32))

    # 用于保存模型
    saver = tf.train.Saver()
    # 初始化
    sess.run(tf.global_variables_initializer())

    # 創(chuàng)建一個(gè)協(xié)調(diào)器,管理線程
    coord = tf.train.Coordinator()
    # 啟動QueueRunner, 此時(shí)文件名隊(duì)列已經(jīng)進(jìn)隊(duì)
    threads = tf.train.start_queue_runners(sess=sess, coord=coord)

    for i in range(6001):
        # 獲取一個(gè)批次的數(shù)據(jù)和標(biāo)簽
        b_image, b_label0, b_label1, b_label2, b_label3 = sess.run(
            [image_batch, label_batch0, label_batch1, label_batch2, label_batch3])
        # 優(yōu)化模型
        sess.run(optimizer, feed_dict={x: b_image, y0: b_label0, y1: b_label1, y2: b_label2, y3: b_label3})

        # 每迭代20次計(jì)算一次loss和準(zhǔn)確率
        if i % 20 == 0:
            # 每迭代2000次降低一次學(xué)習(xí)率
            if i % 2000 == 0:
                sess.run(tf.assign(lr, lr / 3))
            acc0, acc1, acc2, acc3, loss_ = sess.run([accuracy0, accuracy1, accuracy2, accuracy3, total_loss],
                                                     feed_dict={x: b_image,
                                                                y0: b_label0,
                                                                y1: b_label1,
                                                                y2: b_label2,
                                                                y3: b_label3})
            learning_rate = sess.run(lr)
            print("Iter:%d  Loss:%.3f  Accuracy:%.2f,%.2f,%.2f,%.2f  Learning_rate:%.4f" % (
            i, loss_, acc0, acc1, acc2, acc3, learning_rate))

            # 保存模型
            # if i == 6000:
            if acc0 > 0.90 and acc1 > 0.90 and acc2 > 0.90 and acc3 > 0.90:
                saver.save(sess, "captcha/models/crack_captcha.model", global_step=i)
                break

                # 通知其他線程關(guān)閉
    coord.request_stop()
    # 其他所有線程關(guān)閉之后,這一函數(shù)才能返回
    coord.join(threads)

  • 測試
# coding: utf-8

import tensorflow as tf
from PIL import Image
from nets import nets_factory
import matplotlib.pyplot as plt


# 不同字符數(shù)量
CHAR_SET_LEN = 10
# 圖片高度
IMAGE_HEIGHT = 60
# 圖片寬度
IMAGE_WIDTH = 160
# 批次
BATCH_SIZE = 1
# tfrecord文件存放路徑
TFRECORD_FILE = "captcha/test.tfrecords"

# placeholder
x = tf.placeholder(tf.float32, [None, 224, 224])


# 從tfrecord讀出數(shù)據(jù)
def read_and_decode(filename):
    # 根據(jù)文件名生成一個(gè)隊(duì)列
    filename_queue = tf.train.string_input_producer([filename])
    reader = tf.TFRecordReader()
    # 返回文件名和文件
    _, serialized_example = reader.read(filename_queue)
    features = tf.parse_single_example(serialized_example,
                                       features={
                                           'image': tf.FixedLenFeature([], tf.string),
                                           'label0': tf.FixedLenFeature([], tf.int64),
                                           'label1': tf.FixedLenFeature([], tf.int64),
                                           'label2': tf.FixedLenFeature([], tf.int64),
                                           'label3': tf.FixedLenFeature([], tf.int64),
                                       })
    # 獲取圖片數(shù)據(jù)
    image = tf.decode_raw(features['image'], tf.uint8)
    # 沒有經(jīng)過預(yù)處理的灰度圖
    image_raw = tf.reshape(image, [224, 224])
    # tf.train.shuffle_batch必須確定shape
    image = tf.reshape(image, [224, 224])
    # 圖片預(yù)處理
    image = tf.cast(image, tf.float32) / 255.0
    image = tf.subtract(image, 0.5)
    image = tf.multiply(image, 2.0)
    # 獲取label
    label0 = tf.cast(features['label0'], tf.int32)
    label1 = tf.cast(features['label1'], tf.int32)
    label2 = tf.cast(features['label2'], tf.int32)
    label3 = tf.cast(features['label3'], tf.int32)

    return image, image_raw, label0, label1, label2, label3


# 獲取圖片數(shù)據(jù)和標(biāo)簽
image, image_raw, label0, label1, label2, label3 = read_and_decode(TFRECORD_FILE)

# 使用shuffle_batch可以隨機(jī)打亂
image_batch, image_raw_batch, label_batch0, label_batch1, label_batch2, label_batch3 = tf.train.shuffle_batch(
    [image, image_raw, label0, label1, label2, label3], batch_size=BATCH_SIZE,
    capacity=50000, min_after_dequeue=10000, num_threads=1)

# 定義網(wǎng)絡(luò)結(jié)構(gòu)
train_network_fn = nets_factory.get_network_fn(
    'alexnet_v2',
    num_classes=CHAR_SET_LEN,
    weight_decay=0.0005,
    is_training=False)

with tf.Session() as sess:
    # inputs: a tensor of size [batch_size, height, width, channels]
    X = tf.reshape(x, [BATCH_SIZE, 224, 224, 1])
    # 數(shù)據(jù)輸入網(wǎng)絡(luò)得到輸出值
    logits0, logits1, logits2, logits3, end_points = train_network_fn(X)

    # 預(yù)測值
    predict0 = tf.reshape(logits0, [-1, CHAR_SET_LEN])
    predict0 = tf.argmax(predict0, 1)

    predict1 = tf.reshape(logits1, [-1, CHAR_SET_LEN])
    predict1 = tf.argmax(predict1, 1)

    predict2 = tf.reshape(logits2, [-1, CHAR_SET_LEN])
    predict2 = tf.argmax(predict2, 1)

    predict3 = tf.reshape(logits3, [-1, CHAR_SET_LEN])
    predict3 = tf.argmax(predict3, 1)

    # 初始化
    sess.run(tf.global_variables_initializer())
    # 載入訓(xùn)練好的模型
    saver = tf.train.Saver()
    saver.restore(sess, 'captcha/models/crack_captcha.model-6000')

    # 創(chuàng)建一個(gè)協(xié)調(diào)器,管理線程
    coord = tf.train.Coordinator()
    # 啟動QueueRunner, 此時(shí)文件名隊(duì)列已經(jīng)進(jìn)隊(duì)
    threads = tf.train.start_queue_runners(sess=sess, coord=coord)

    for i in range(10):
        # 獲取一個(gè)批次的數(shù)據(jù)和標(biāo)簽
        b_image, b_image_raw, b_label0, b_label1, b_label2, b_label3 = sess.run([image_batch,
                                                                                 image_raw_batch,
                                                                                 label_batch0,
                                                                                 label_batch1,
                                                                                 label_batch2,
                                                                                 label_batch3])
        # 顯示圖片
        img = Image.fromarray(b_image_raw[0], 'L')
        plt.imshow(img)
        plt.axis('off')
        plt.show()
        # 打印標(biāo)簽
        print('label:', b_label0, b_label1, b_label2, b_label3)
        # 預(yù)測
        label0, label1, label2, label3 = sess.run([predict0, predict1, predict2, predict3], feed_dict={x: b_image})
        # 打印預(yù)測值
        print('predict:', label0, label1, label2, label3)

        # 通知其他線程關(guān)閉
    coord.request_stop()
    # 其他所有線程關(guān)閉之后,這一函數(shù)才能返回
    coord.join(threads)

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