def __init__(self, width, height, gl_format, data, 
                 extension=None, decoder=None):
        if not _is_pow2(width) or not _is_pow2(height):
            raise ImageException('Dimensions of %r must be powers of 2' % self)

        super(CompressedImageData, self).__init__(width, height)
        self.data = data
        self.gl_format = gl_format
        self.extension = extension
        self.decoder = decoder
        self.mipmap_data = []
Compute the l1 distance measure
dataset/ETHPy150Open ardekantur/pyglet/pyglet/image/__init__.py/CompressedImageData.__init__--crossover with--dataset/ETHPy150Open bolme/pyvision/src/pyvision/other/distance.py/l1