colorimetry.py 文件源码

def wavelength_to_XYZ(wavelength, observer='1931_2deg'):
    ''' Uses tristimulus color matching functions to map a awvelength to XYZ
        coordinates.

    Args:
        wavelength (`float`): wavelength in nm.

        observer (`str`): CIE observer name, must be 1931_2deg.

    Returns:
        `numpy.ndarray`: array with last dimension corresponding to X, Y, Z.

    '''
    wavelength = np.asarray(wavelength, dtype=config.precision)

    cmf = get_cmf(observer)
    wvl, X, Y, Z = cmf['wvl'], cmf['X'], cmf['Y'], cmf['Z']

    ia = {'bounds_error': False, 'fill_value': 0, 'assume_sorted': True}
    f_X, f_Y, f_Z = interp1d(wvl, X, **ia), interp1d(wvl, Y, **ia), interp1d(wvl, Z, **ia)
    x, y, z = f_X(wavelength), f_Y(wavelength), f_Z(wavelength)

    shape = wavelength.shape
    return np.stack((x, y, z), axis=len(shape))