Tensorflow踩坑系列---TFRECORD文件读写

补充：TFRECORD文件学习

https://blog.csdn.net/briblue/article/details/80789608

import tensorflow as tf
import os
import random
import sys

#生成的tfrecord文件数量
_NUM_BLOCK = 2
#源图片位置
DATASET_DIR = "./Images/SourceImgs/"
#目标文件位置
GOALSET_DIR = "./Images/TFImgs/"

GOALTFSET_DIR = "./Images/TFSourceImgs/"

QUEUE_DIR = "./Images/QueueImgs/"

一：生成TFRECORD文件

（一）获取图片信息

#获取图片的信息
def get_file_info(dataSet_dir = DATASET_DIR):
    files_name = []
    for filename in os.listdir(dataSet_dir):
        files_name.append(os.path.join(dataSet_dir,filename))
        
    return files_name

（二）写入TFRECORD文件

with tf.Session() as sess:
    files_list = get_file_info()
    num_per_block = len(files_list)//_NUM_BLOCK
    for _id in range(_NUM_BLOCK):
        tfr_name = "image_%d.tfrecord"%(_id+1)
        tfr_dir = os.path.join(GOALSET_DIR,tfr_name)
        with tf.python_io.TFRecordWriter(tfr_dir) as writer:
            start_idx = _id*num_per_block
            end_idx = min((_id+1)*num_per_block,len(files_list))
            
            for i in range(start_idx,end_idx):
                try:
                    sys.stdout.write("
>>Converting images %d/%d to block %d"%(i+1,len(files_list),_id+1))
                    sys.stdout.flush()
                    #读取图片信息
                    image_data = tf.gfile.FastGFile(files_list[i],'rb').read()
                    #获取标签
                    label = files_list[i].split("/")[-1].split(".")[0]
                    
                    example = _format_record(image_data,label)
                    
                    writer.write(example.SerializePartialToString())
                except IOError as e:
                    print("Could not read:",files_list[i])
                    print("Error",e)
                    print("Skip it
")
    sys.stdout.write("
")
    sys.stdout.flush()

二：直接读取TFRECORD文件

（一）解析文件

def _parse_record(example_proto):
    features = {
        'label':tf.FixedLenFeature((),tf.string),
        'data':tf.FixedLenFeature((),tf.string)
    }
    parsed_features = tf.parse_single_example(example_proto,features=features)
    return parsed_features

（二）读取所有文件

with tf.Session() as sess:
    tf_files = []
    for fn in os.listdir(GOALSET_DIR):
        tf_files.append(os.path.join(GOALSET_DIR,fn))
        
    dataSet = tf.data.TFRecordDataset(tf_files) #读取TF文件---可以选择一次性读取所有的tfrecord文件
    dataSet = dataSet.map(_parse_record) #解析数据
    
    iterator = dataSet.make_one_shot_iterator()
    
    sess.run(tf.local_variables_initializer())
    while True:
        try:
            Singledata = sess.run(iterator.get_next())
            label = Singledata['label'].decode()
            image_data = Singledata['data']
            tf.gfile.GFile(os.path.join(GOALTFSET_DIR,"%s.jpg"%label),"wb").write(image_data)
        except BaseException as e:
            print("Read finish!!!")
            break

三：使用文件队列读取多个tfrecord文件

tf_files = []
for fn in os.listdir(GOALSET_DIR):
    tf_files.append(os.path.join(GOALSET_DIR,fn))

#string_input_producer产生文件名队列
filename_queue = tf.train.string_input_producer(tf_files,shuffle=True,num_epochs=3) #获取了多个tfrecord文件

#reader从文件名队列中读取数据
reader = tf.TFRecordReader()
key,value = reader.read(filename_queue) #返回文件名和文件内容
features = tf.parse_single_example(value,features={
        'label':tf.FixedLenFeature((),tf.string),
        'data':tf.FixedLenFeature((),tf.string)
    })
img_data = features['data']
label = features['label']

image_batch,label_batch = tf.train.shuffle_batch([img_data,label],batch_size=8,num_threads=2,allow_smaller_final_batch=True,
                                                capacity=500,min_after_dequeue=100) 
with tf.Session() as sess:
    sess.run(tf.global_variables_initializer()) #初始化上面的全局变量
    sess.run(tf.local_variables_initializer()) #初始化上面的局部变量
    
    coord = tf.train.Coordinator()
    #启动start_queue_runners之后，才会开始填充队列
    threads = tf.train.start_queue_runners(sess=sess,coord=coord)
    j = 1
    try:
        while not coord.should_stop():
            images_data,labels_data = sess.run([image_batch,label_batch])
            for i in range(len(images_data)):
                with open(QUEUE_DIR+"%s-%d.jpg"%(labels_data[i].decode(),j),"wb") as f:
                    f.write(images_data[i])
                j+=1
    except BaseException as e:
            print("read all files")
    finally:
        coord.request_stop() #将读取文件的线程关闭
    coord.join(threads) #线程回收，将读取文件的子线程加入主线程