image_testing.py 文件源码

def makeDiffImage(im1, im2):
    """Return image array showing the differences between im1 and im2.

    Handles images of different shape. Alpha channels are not compared.
    """
    ds = im1.shape
    es = im2.shape

    diff = np.empty((max(ds[0], es[0]), max(ds[1], es[1]), 4), dtype=int)
    diff[..., :3] = 128
    diff[..., 3] = 255
    diff[:ds[0], :ds[1], :min(ds[2], 3)] += im1[..., :3]
    diff[:es[0], :es[1], :min(es[2], 3)] -= im2[..., :3]
    diff = np.clip(diff, 0, 255).astype(np.ubyte)
    return diff