public static ColorHunterLab convertXyzToHunterLab(final double x, final double y, final double z) {
        final double l = 10 * Math.sqrt(y);
        final double a = y == 0.0 ? 0.0 : 17.5 * ((1.02 * x - y) / Math.sqrt(y));
        final double b = y == 0.0 ? 0.0 : 7 * ((y - 0.847 * z) / Math.sqrt(y));

        return new ColorHunterLab(l, a, b);
    }
DIN99o.

@param l99o lightness of color.
@param a99o position between red and green.
@param b99o position between yellow and blue.
@return DIN99o colors converted to CIELab color space.
@see <a href=
     "https://de.wikipedia.org/w/index.php?title=Diskussion:DIN99-Farbraum">https://de.wikipedia.org/w/index.php?title=Diskussion:DIN99-Farbraum</a>
src/main/java/org/apache/commons/imaging/color/ColorConversions.java