为图像-文本配对数据构造TfRecord

时间:2019-04-20 23:44:16

标签: python tensorflow tensorflow-datasets tfrecord

我坚持让tfrecords用于图文对数据。

这是从numpy图片特征数组和文本文件创建tfrecord的代码,

z

此后,我无法创建数据集:

def npy_to_tfrecords(numpy_array, text_file, output_file):
      f = open(text_file)

      # write records to a tfrecords file
      writer = tf.python_io.TFRecordWriter(output_file)

      # Loop through all the features you want to write
      for X, line in zip(numpy_array, f) :
         #let say X is of np.array([[...][...]])
         #let say y is of np.array[[0/1]]

         txt = "{}".format(line[:-1])
         txt = txt.encode()

         # Feature contains a map of string to feature proto objects
         feature = {}
         feature['x'] = tf.train.Feature(float_list=tf.train.FloatList(value=X.flatten()))
         feature['y'] = tf.train.Feature(bytes_list=tf.train.BytesList(value=[txt]))

         # Construct the Example proto object
         example = tf.train.Example(features=tf.train.Features(feature=feature))

         # Serialize the example to a string
         serialized = example.SerializeToString()

         # write the serialized objec to the disk
         writer.write(serialized)
      writer.close()

我保留。得到错误:

def load_data_tfr():

   train = tf.data.TFRecordDataset("train.tfrecord")

   # example proto decode
   def _parse_function1(example_proto):
      keys_to_features = {'x': tf.FixedLenFeature(2048, tf.float32),
                          'y': tf.VarLenFeature(tf.string) } 
      parsed_features = tf.parse_single_example(example_proto, keys_to_features)
      return {"x": parsed_features['x'], "y":  parsed_features['y']} # ['x'], parsed_features['y']

   # Parse the record into tensors.
   train = train.map(_parse_function1)

   return train
train_data = load_data_tfr()
random.shuffle(train_data)

有帮助吗?谢谢。

1 个答案:

答案 0 :(得分:1)

MapDataset没有长度。

因此,将这两行放在代码的最上方。

import tensorflow as tf
tf.enable_eager_execution()

然后尝试

iterator = train_data.make_one_shot_iterator()
image, label = iterator.get_next()

当然,我假设您的tfrecord部分没有任何错误。

根据Tensorflow教程,图像以字节格式而不是np数组保存。