Tile.py 文件源码

def _unpack_bitplanes(self, data):
        """The values that make up a row of pixels are organized like:
        [bp1-row1] [bp2-row1] [bp3-row1] [bp4-row1]...
        [bp1-row8] [bp2-row8] [bp3-row8] [bp4-row8]

        Returns a list of lists containing bitplane values (bytes).
        """
        planes = [[], [], [], []]
        data_iter = Struct('c').iter_unpack(data)

        for bp in data_iter:
            planes[0].extend(*bp)
            planes[1].extend(*next(data_iter))
            planes[2].extend(*next(data_iter))
            planes[3].extend(*next(data_iter))

        return planes