def from_folder()

in tensorflow_examples/lite/model_maker/core/data_util/image_dataloader.py [0:0]


  def from_folder(cls, filename, shuffle=True):
    """Image analysis for image classification load images with labels.

    Assume the image data of the same label are in the same subdirectory.

    Args:
      filename: Name of the file.
      shuffle: boolean, if shuffle, random shuffle data.

    Returns:
      ImageDataset containing images and labels and other related info.
    """
    data_root = os.path.abspath(filename)

    # Assumes the image data of the same label are in the same subdirectory,
    # gets image path and label names.
    all_image_paths = list(tf.io.gfile.glob(data_root + r'/*/*'))
    all_image_size = len(all_image_paths)
    if all_image_size == 0:
      raise ValueError('Image size is zero')

    if shuffle:
      # Random shuffle data.
      random.shuffle(all_image_paths)

    label_names = sorted(
        name for name in os.listdir(data_root)
        if os.path.isdir(os.path.join(data_root, name)))
    all_label_size = len(label_names)
    label_to_index = dict(
        (name, index) for index, name in enumerate(label_names))
    all_image_labels = [
        label_to_index[os.path.basename(os.path.dirname(path))]
        for path in all_image_paths
    ]

    path_ds = tf.data.Dataset.from_tensor_slices(all_image_paths)

    autotune = tf.data.AUTOTUNE
    image_ds = path_ds.map(load_image, num_parallel_calls=autotune)

    # Loads label.
    label_ds = tf.data.Dataset.from_tensor_slices(
        tf.cast(all_image_labels, tf.int64))

    # Creates  a dataset if (image, label) pairs.
    image_label_ds = tf.data.Dataset.zip((image_ds, label_ds))

    tf.compat.v1.logging.info(
        'Load image with size: %d, num_label: %d, labels: %s.', all_image_size,
        all_label_size, ', '.join(label_names))
    return ImageClassifierDataLoader(image_label_ds, all_image_size,
                                     label_names)