tf.TextLineReader Outputs the lines of a file delimited by newlines E.g. text files, CSV files
tf.FixedLengthRecordReader Outputs the entire file when all files have same fixed lengths E.g. each MNIST file has 28 x 28 pixels, CIFAR-10 32 x 32 x 3
tf.WholeFileReader Outputs the entire file content
tf.TFRecordReader Reads samples from TensorFlow’s own binary format (TFRecord)
