colorimetry.py 文件源码

def XYZ_to_uvprime(XYZ):
    ''' Converts XYZ points to u'v' points.

    Args:
        XYZ (`numpy.ndarray`): ndarray with last dimension corresponding to
            X, Y, Z.

    Returns:
        `tuple` containing:

            `numpy.ndarray`: u' coordinates.

            `numpy.ndarray`: u' coordinates.

    '''
    XYZ = np.asarray(XYZ)
    X, Y, Z = XYZ[..., 0], XYZ[..., 1], XYZ[..., 2]
    u = (4 * X) / (X + 15 * Y + 3 * Z)
    v = (9 * Y) / (X + 15 * Y + 3 * Z)

    shape = u.shape
    return np.stack((u, v), axis=len(shape))