tensorflow_backend.py 文件源码

def spatial_2d_padding(x, padding=(1, 1), dim_ordering='default'):
    """Pads the 2nd and 3rd dimensions of a 4D tensor
    with "padding[0]" and "padding[1]" (resp.) zeros left and right.

    # Returns
        A padded 4D tensor.

    # Raises
        ValueError: if `dim_ordering` is neither `tf` or `th`.
    """
    if dim_ordering == 'default':
        dim_ordering = image_dim_ordering()
    if dim_ordering not in {'th', 'tf'}:
        raise ValueError('Unknown dim_ordering ' + str(dim_ordering))

    if dim_ordering == 'th':
        pattern = [[0, 0], [0, 0],
                   [padding[0], padding[0]], [padding[1], padding[1]]]
    else:
        pattern = [[0, 0],
                   [padding[0], padding[0]], [padding[1], padding[1]],
                   [0, 0]]
    return tf.pad(x, pattern)