tensorflow實現驗證碼識別案例


1、知識點

"""
驗證碼分析:
    對圖片進行分析:
                1、分割識別
                2、整體識別
輸出:[3,5,7]  -->softmax轉為概率[0.04,0.16,0.8] ---> 交叉熵計算損失值 (目標值和預測值的對數) 
tf.argmax(預測值,2)
驗證碼樣例:[NAZP] [XCVB] [WEFW] ,都是字母的
"""

2、將數據寫入TFRecords

import tensorflow as tf
import os
os.environ['TF_CPP_MIN_LOG_LEVEL'] = '2'


FLAGS = tf.app.flags.FLAGS
tf.app.flags.DEFINE_string("tfrecords_dir", "./tfrecords/captcha.tfrecords", "驗證碼tfrecords文件")
tf.app.flags.DEFINE_string("captcha_dir", "../data/Genpics/", "驗證碼圖片路徑")
tf.app.flags.DEFINE_string("letter", "ABCDEFGHIJKLMNOPQRSTUVWXYZ", "驗證碼字符的種類")


def dealwithlabel(label_str):

    # 構建字符索引 {0:'A', 1:'B'......}
    num_letter = dict(enumerate(list(FLAGS.letter)))

    # 鍵值對反轉 {'A':0, 'B':1......}
    letter_num = dict(zip(num_letter.values(), num_letter.keys()))

    print(letter_num)

    # 構建標簽的列表
    array = []

    # 給標簽數據進行處理[[b"NZPP"]......]
    for string in label_str:

        letter_list = []# [1,2,3,4]

        # 修改編碼,b'FVQJ'到字符串,並且循環找到每張驗證碼的字符對應的數字標記
        for letter in string.decode('utf-8'):
            letter_list.append(letter_num[letter])

        array.append(letter_list)

    # [[13, 25, 15, 15], [22, 10, 7, 10], [22, 15, 18, 9], [16, 6, 13, 10], [1, 0, 8, 17], [0, 9, 24, 14].....]
    print(array)

    # 將array轉換成tensor類型
    label = tf.constant(array)

    return label


def get_captcha_image():
    """
    獲取驗證碼圖片數據
    :param file_list: 路徑+文件名列表
    :return: image
    """
    # 構造文件名
    filename = []

    for i in range(6000):
        string = str(i) + ".jpg"
        filename.append(string)

    # 構造路徑+文件
    file_list = [os.path.join(FLAGS.captcha_dir, file) for file in filename]

    # 構造文件隊列
    file_queue = tf.train.string_input_producer(file_list, shuffle=False)

    # 構造閱讀器
    reader = tf.WholeFileReader()

    # 讀取圖片數據內容
    key, value = reader.read(file_queue)

    # 解碼圖片數據
    image = tf.image.decode_jpeg(value)

    image.set_shape([20, 80, 3])

    # 批處理數據 [6000, 20, 80, 3]
    image_batch = tf.train.batch([image], batch_size=6000, num_threads=1, capacity=6000)

    return image_batch


def get_captcha_label():
    """
    讀取驗證碼圖片標簽數據
    :return: label
    """
    file_queue = tf.train.string_input_producer(["../data/Genpics/labels.csv"], shuffle=False)

    reader = tf.TextLineReader()

    key, value = reader.read(file_queue)

    records = [[1], ["None"]]

    number, label = tf.decode_csv(value, record_defaults=records)

    # [["NZPP"], ["WKHK"], ["ASDY"]]
    label_batch = tf.train.batch([label], batch_size=6000, num_threads=1, capacity=6000)

    return label_batch


def write_to_tfrecords(image_batch, label_batch):
    """
    將圖片內容和標簽寫入到tfrecords文件當中
    :param image_batch: 特征值
    :param label_batch: 標簽紙
    :return: None
    """
    # 轉換類型
    label_batch = tf.cast(label_batch, tf.uint8)

    print(label_batch)

    # 建立TFRecords 存儲器
    writer = tf.python_io.TFRecordWriter(FLAGS.tfrecords_dir)

    # 循環將每一個圖片上的數據構造example協議塊,序列化后寫入
    for i in range(6000):
        # 取出第i個圖片數據,轉換相應類型,圖片的特征值要轉換成字符串形式
        image_string = image_batch[i].eval().tostring()

        # 標簽值,轉換成整型
        label_string = label_batch[i].eval().tostring()

        # 構造協議塊
        example = tf.train.Example(features=tf.train.Features(feature={
            "image": tf.train.Feature(bytes_list=tf.train.BytesList(value=[image_string])),
            "label": tf.train.Feature(bytes_list=tf.train.BytesList(value=[label_string]))
        }))

        writer.write(example.SerializeToString())

    # 關閉文件
    writer.close()

    return None


if __name__ == "__main__":

    # 獲取驗證碼文件當中的圖片
    image_batch = get_captcha_image()

    # 獲取驗證碼文件當中的標簽數據
    label = get_captcha_label()

    print(image_batch, label)

    with tf.Session() as sess:

        coord = tf.train.Coordinator()

        threads = tf.train.start_queue_runners(sess=sess, coord=coord)

        # [b'NZPP' b'WKHK' b'WPSJ' ..., b'FVQJ' b'BQYA' b'BCHR']
        label_str = sess.run(label)

        print(label_str)

        # 處理字符串標簽到數字張量
        label_batch = dealwithlabel(label_str)

        print(label_batch)

        # 將圖片數據和內容寫入到tfrecords文件當中
        write_to_tfrecords(image_batch, label_batch)

        coord.request_stop()

        coord.join(threads)
View Code

3、數據存在百度雲(小白號)

4、標准代碼

import tensorflow as tf

FLAGS = tf.app.flags.FLAGS

tf.app.flags.DEFINE_string("captcha_dir", "./tfrecords/captcha.tfrecords", "驗證碼數據的路徑")
tf.app.flags.DEFINE_integer("batch_size", 100, "每批次訓練的樣本數")
tf.app.flags.DEFINE_integer("label_num", 4, "每個樣本的目標值數量")
tf.app.flags.DEFINE_integer("letter_num", 26, "每個目標值取的字母的可能心個數")


# 定義一個初始化權重的函數
def weight_variables(shape):
    w = tf.Variable(tf.random_normal(shape=shape, mean=0.0, stddev=1.0))
    return w


# 定義一個初始化偏置的函數
def bias_variables(shape):
    b = tf.Variable(tf.constant(0.0, shape=shape))
    return b


def read_and_decode():
    """
    讀取驗證碼數據API
    :return: image_batch, label_batch
    """
    # 1、構建文件隊列
    file_queue = tf.train.string_input_producer([FLAGS.captcha_dir])

    # 2、構建閱讀器,讀取文件內容,默認一個樣本
    reader = tf.TFRecordReader()

    # 讀取內容
    key, value = reader.read(file_queue)

    # tfrecords格式example,需要解析
    features = tf.parse_single_example(value, features={
        "image": tf.FixedLenFeature([], tf.string),
        "label": tf.FixedLenFeature([], tf.string),
    })

    # 解碼內容,字符串內容
    # 1、先解析圖片的特征值
    image = tf.decode_raw(features["image"], tf.uint8)
    # 1、先解析圖片的目標值
    label = tf.decode_raw(features["label"], tf.uint8)

    # print(image, label)

    # 改變形狀
    image_reshape = tf.reshape(image, [20, 80, 3])

    label_reshape = tf.reshape(label, [4])

    print(image_reshape, label_reshape)

    # 進行批處理,每批次讀取的樣本數 100, 也就是每次訓練時候的樣本
    image_batch, label_btach = tf.train.batch([image_reshape, label_reshape], batch_size=FLAGS.batch_size, num_threads=1, capacity=FLAGS.batch_size)

    print(image_batch, label_btach)
    return image_batch, label_btach


def fc_model(image):
    """
    進行預測結果
    :param image: 100圖片特征值[100, 20, 80, 3]
    :return: y_predict預測值[100, 4 * 26]
    """
    with tf.variable_scope("model"):
        # 將圖片數據形狀轉換成二維的形狀
        image_reshape = tf.reshape(image, [-1, 20 * 80 * 3])

        # 1、隨機初始化權重偏置
        # matrix[100, 20 * 80 * 3] * [20 * 80 * 3, 4 * 26] + [104] = [100, 4 * 26]
        weights = weight_variables([20 * 80 * 3, 4 * 26])
        bias = bias_variables([4 * 26])

        # 進行全連接層計算[100, 4 * 26]
        y_predict = tf.matmul(tf.cast(image_reshape, tf.float32), weights) + bias

    return y_predict


def predict_to_onehot(label):
    """
    將讀取文件當中的目標值轉換成one-hot編碼
    :param label: [100, 4]      [[13, 25, 15, 15], [19, 23, 20, 16]......]
    :return: one-hot
    """
    # 進行one_hot編碼轉換,提供給交叉熵損失計算,准確率計算[100, 4, 26]
    label_onehot = tf.one_hot(label, depth=FLAGS.letter_num, on_value=1.0, axis=2)

    print(label_onehot)

    return label_onehot


def captcharec():
    """
    驗證碼識別程序
    :return:
    """
    # 1、讀取驗證碼的數據文件 label_btch [100 ,4]
    image_batch, label_batch = read_and_decode()

    # 2、通過輸入圖片特征數據,建立模型,得出預測結果
    # 一層,全連接神經網絡進行預測
    # matrix [100, 20 * 80 * 3] * [20 * 80 * 3, 4 * 26] + [104] = [100, 4 * 26]
    y_predict = fc_model(image_batch)

    #  [100, 4 * 26]
    print(y_predict)

    # 3、先把目標值轉換成one-hot編碼 [100, 4, 26]
    y_true = predict_to_onehot(label_batch)

    # 4、softmax計算, 交叉熵損失計算
    with tf.variable_scope("soft_cross"):
        # 求平均交叉熵損失 ,y_true [100, 4, 26]--->[100, 4*26]
        loss = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(
            labels=tf.reshape(y_true, [FLAGS.batch_size, FLAGS.label_num * FLAGS.letter_num]),
            logits=y_predict))
    # 5、梯度下降優化損失
    with tf.variable_scope("optimizer"):

        train_op = tf.train.GradientDescentOptimizer(0.01).minimize(loss)

    # 6、求出樣本的每批次預測的准確率是多少 三維比較
    with tf.variable_scope("acc"):

        # 比較每個預測值和目標值是否位置(4)一樣    y_predict [100, 4 * 26]---->[100, 4, 26]
        equal_list = tf.equal(tf.argmax(y_true, 2), tf.argmax(tf.reshape(y_predict, [FLAGS.batch_size, FLAGS.label_num, FLAGS.letter_num]), 2))

        # equal_list  100個樣本   [1, 0, 1, 0, 1, 1,..........]
        accuracy = tf.reduce_mean(tf.cast(equal_list, tf.float32))

    # 定義一個初始化變量的op
    init_op = tf.global_variables_initializer()

    # 開啟會話訓練
    with tf.Session() as sess:
        sess.run(init_op)

        # 定義線程協調器和開啟線程(有數據在文件當中讀取提供給模型)
        coord = tf.train.Coordinator()

        # 開啟線程去運行讀取文件操作
        threads = tf.train.start_queue_runners(sess, coord=coord)

        # 訓練識別程序
        for i in range(5000):

            sess.run(train_op)

            print("第%d批次的准確率為:%f" % (i, accuracy.eval()))

        # 回收線程
        coord.request_stop()

        coord.join(threads)

    return None


if __name__ == "__main__":
    captcharec()
View Code

5、自寫代碼

# coding = utf-8

import tensorflow as tf
from tensorflow.contrib.slim.python.slim.nets.inception_v3 import inception_v3_base
import  os
"""
驗證碼分析:
    對圖片進行分析:
                1、分割識別
                2、整體識別
輸出:[3,5,7]  -->softmax轉為概率[0.04,0.16,0.8] ---> 交叉熵計算損失值 (目標值和預測值的對數) 
tf.argmax(預測值,2)
"""
FLAGS = tf.app.flags.FLAGS
tf.app.flags.DEFINE_string("captcha_dir","./tfrecords/captcha.tfrecords","驗證碼數據路徑")
tf.app.flags.DEFINE_integer("batch_size",100,"讀取批次")
tf.app.flags.DEFINE_integer("label_num", 4, "每個樣本的目標值數量")
tf.app.flags.DEFINE_integer("letter_num", 26, "每個目標值取的字母的可能心個數")


def weight_variable(shape):
    w = tf.Variable(tf.random_normal(shape=shape,mean=0.0,stddev=1.0,))
    return w
def bias_variable(shape):
    b = tf.Variable(tf.random_normal(shape=shape,mean=0.0,stddev=1.0))
    return b

def captcharec():
    """
    驗證碼識別
    :return:
    """
    #1、讀取驗證碼的數據文件
    file_queue = tf.train.string_input_producer([FLAGS.captcha_dir])

    #2、創建閱讀器,解析example
    reader = tf.TFRecordReader()
    key ,value = reader.read(file_queue)
    features = tf.parse_single_example(value,features={
        "image":tf.FixedLenFeature([],tf.string),
        "label": tf.FixedLenFeature([], tf.string)
    })
    #解碼操作
    image = tf.decode_raw(features["image"],tf.uint8)
    label = tf.decode_raw(features["label"],tf.uint8)
    print(image,label)

    #修改形狀
    image_reshape = tf.reshape(image,[20,80,3])
    label_reshape = tf.reshape(label, [4])

    #進行批處理,每次讀取100個樣本
    image_batch,label_batch = tf.train.batch([image_reshape,label_reshape],batch_size=100,num_threads=1,capacity=20)
    print(image_batch, label_batch)
    return image_batch,label_batch

def fc_model(image_batch):
    #1、初始化權重和偏置
    w = weight_variable([20*80*3,4*26])
    b = bias_variable([4*26])


    #模型 x [100,20*80*3]  w [20*80*3,4]          y_true [100,4]
    #對輸入進行矩陣轉換
    image = tf.reshape(image_batch,[-1,20*80*3])
    y_predict = tf.matmul(tf.cast(image,tf.float32),w) + b

    ############收集變量########
    tf.summary.histogram("w",w)
    tf.summary.histogram("b",b)
    merged = tf.summary.merge_all()
    return y_predict,merged

#[100,4]
def predict_to_onehot(label_batch):
    y_true = tf.one_hot(label_batch,on_value=1.0,depth=26,axis=2)
    return y_true


if __name__ == '__main__':
    image_batch, label_batch = captcharec()
    y_predict,merged_his =fc_model(image_batch)
    y_true = predict_to_onehot(label_batch)

    #計算交叉熵
    loss = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(labels=tf.reshape(y_true,[100,4*26]),logits=y_predict))

    #梯度下降優化
    train_op = tf.train.GradientDescentOptimizer(0.001).minimize(loss)

    #准確率
    equal_list = tf.equal(tf.argmax(y_true,2),tf.argmax(tf.reshape(y_predict,[100,4,26]),2))
    accuracy = tf.reduce_mean(tf.cast(equal_list,tf.float32))

    #####收集變量###############
    tf.summary.scalar("losses",loss)
    tf.summary.scalar("accuracy",accuracy)
    merged_scalar = tf.summary.merge_all()

    ############保存模型####
    saver = tf.train.Saver()

    init_op = tf.global_variables_initializer()
    with tf.Session() as sess:
        sess.run(init_op)

        fileWriter = tf.summary.FileWriter("./vc",graph=sess.graph)
        #創建線程協調器
        coord = tf.train.Coordinator()

        #開啟線程
        threads = tf.train.start_queue_runners(sess,coord=coord)
        IS_TRAIN =1

        # if os.path.exists("./vertifycode/checkpoint"):
        #     IS_TRAIN = 0

        if IS_TRAIN==1:
            #######訓練模型###############
            # if os.path.exists("./vertifycode/checkpoint"):
            #     saver.restore(sess, "./vertifycode/vertifycode_model")

            for i in range(2000):
                sess.run(train_op)
                summary_his = sess.run(merged_his)
                summary_scalar = sess.run(merged_scalar)
                fileWriter.add_summary(summary_scalar,i)
                fileWriter.add_summary(summary_his,i)
                print("訓練第%d次的准確率為:%f" %(i,accuracy.eval()))

            #######保存模型#############
            saver.save(sess,"./vertifycode/vertifycode_model")
        else:
            ##########測試模型##################
            for i in range(10):
                saver.restore(sess, "./vertifycode/vertifycode_model")
                # print("第%d張圖片的准確率為:%f" % (
                #     i,
                #     tf.argmax(y_test, 2).eval(),
                #     tf.argmax(y_predict,2).eval()
                #                           ))

        #停止線程
        coord.request_stop()
        coord.join(threads)

 


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