tensorflow_backend.py 文件源码

def asymmetric_spatial_2d_padding(x, top_pad=1, bottom_pad=1,
                                  left_pad=1, right_pad=1,
                                  dim_ordering='default'):
    '''Pad the rows and columns of a 4D tensor
    with "top_pad", "bottom_pad", "left_pad", "right_pad" (resp.) zeros
    rows on top, bottom; cols on left, right.
    '''
    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],
                   [top_pad, bottom_pad],
                   [left_pad, right_pad]]
    else:
        pattern = [[0, 0],
                   [top_pad, bottom_pad],
                   [left_pad, right_pad],
                   [0, 0]]
    return tf.pad(x, pattern)