ColorUtils.java 文件源码

/**
 * Returns the luminance of a color as a float between {@code 0.0} and {@code 1.0}.
 * <p>Defined as the Y component in the XYZ representation of {@code color}.</p>
 */
@FloatRange(from = 0.0, to = 1.0)
public static double calculateLuminance(@ColorInt int color) {
    final double[] result = getTempDouble3Array();
    colorToXYZ(color, result);
    // Luminance is the Y component
    return result[1] / 100;
}