_swf.py 文件源码

def __init__(self, im):
        DefinitionTag.__init__(self)
        self.tagtype = 36 # DefineBitsLossless2

        # convert image (note that format is ARGB)
        # even a grayscale image is stored in ARGB, nevertheless,
        # the fabilous deflate compression will make it that not much
        # more data is required for storing (25% or so, and less than 10%
        # when storing RGB as ARGB).

        if len(im.shape) == 3:
            if im.shape[2] in [3, 4]:
                tmp = np.ones((im.shape[0], im.shape[1], 4),
                              dtype=np.uint8) * 255
                for i in range(3):
                    tmp[:, :, i + 1] = im[:, :, i]
                if im.shape[2] == 4:
                    tmp[:, :, 0] = im[:, :, 3]  # swap channel where alpha is
            else:  # pragma: no cover
                raise ValueError("Invalid shape to be an image.")

        elif len(im.shape) == 2:
            tmp = np.ones((im.shape[0], im.shape[1], 4), dtype=np.uint8)*255
            for i in range(3):
                tmp[:, :, i + 1] = im[:, :]
        else:  # pragma: no cover
            raise ValueError("Invalid shape to be an image.")

        # we changed the image to uint8 4 channels.
        # now compress!
        self._data = zlib.compress(tmp.tostring(), zlib.DEFLATED)
        self.imshape = im.shape