学习谷歌的深度学习终于有点眉目了,给大家分享我的Tensorflow学习历程。
tensorflow的官方中文文档比较生涩,数据集一直采用的MNIST二进制数据集。并没有过多讲述怎么构建自己的图片数据集tfrecords。
流程是:制作数据集—读取数据集—-加入队列
先贴完整的代码:
#encoding=utf-8import osimport tensorflow as tffrom PIL import Imagecwd = os.getcwd()classes = {'test','test1','test2'}#制作二进制数据def create_record(): writer = tf.python_io.TFRecordWriter("train.tfrecords") for index, name in enumerate(classes): class_path = cwd +"/"+ name+"/" for img_name in os.listdir(class_path): img_path = class_path + img_name img = Image.open(img_path) img = img.resize((64, 64)) img_raw = img.tobytes() #将图片转化为原生bytes print index,img_raw example = tf.train.Example( features=tf.train.Features(feature={ "label": tf.train.Feature(int64_list=tf.train.Int64List(value=[index])), 'img_raw': tf.train.Feature(bytes_list=tf.train.BytesList(value=[img_raw])) })) writer.write(example.SerializeToString()) writer.close()data = create_record()#读取二进制数据def read_and_decode(filename): # 创建文件队列,不限读取的数量 filename_queue = tf.train.string_input_producer([filename]) # create a reader from file queue reader = tf.TFRecordReader() # reader从文件队列中读入一个序列化的样本 _, serialized_example = reader.read(filename_queue) # get feature from serialized example # 解析符号化的样本 features = tf.parse_single_example( serialized_example, features={ 'label': tf.FixedLenFeature([], tf.int64), 'img_raw': tf.FixedLenFeature([], tf.string) } ) label = features['label'] img = features['img_raw'] img = tf.decode_raw(img, tf.uint8) img = tf.reshape(img, [64, 64, 3]) img = tf.cast(img, tf.float32) * (1. / 255) - 0.5 label = tf.cast(label, tf.int32) return img, labelif __name__ == '__main__': if 0: data = create_record("train.tfrecords") else: img, label = read_and_decode("train.tfrecords") print "tengxing",img,label #使用shuffle_batch可以随机打乱输入 next_batch挨着往下取 # shuffle_batch才能实现[img,label]的同步,也即特征和label的同步,不然可能输入的特征和label不匹配 # 比如只有这样使用,才能使img和label一一对应,每次提取一个image和对应的label # shuffle_batch返回的值就是RandomShuffleQueue.dequeue_many()的结果 # Shuffle_batch构建了一个RandomShuffleQueue,并不断地把单个的[img,label],送入队列中 img_batch, label_batch = tf.train.shuffle_batch([img, label], batch_size=4, capacity=2000, min_after_dequeue=1000) # 初始化所有的op init = tf.initialize_all_variables() with tf.Session() as sess: sess.run(init) # 启动队列 threads = tf.train.start_queue_runners(sess=sess) for i in range(5): print img_batch.shape,label_batch val, l = sess.run([img_batch, label_batch]) # l = to_categorical(l, 12) print(val.shape, l)
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