Java HSL Color Convert hueFromColor(Color c)

Description

hue From Color

License

Open Source License

Declaration

public static float hueFromColor(Color c) 

Method Source Code

//package com.java2s;
/* -*- tab-width: 4 -*-/*from  www .j  a  va2  s  .c  o m*/
 *
 * Electric(tm) VLSI Design System
 *
 * File: Util.java
 *
 * Copyright (c) 2009, Oracle and/or its affiliates. All rights reserved.
 *
 * Electric(tm) is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * Electric(tm) is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Electric(tm); see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, Mass 02111-1307, USA.
 */

import java.awt.*;

public class Main {
    public static float hueFromColor(Color c) {
        double r = c.getRed() / 255.;
        double g = c.getGreen() / 255.;
        double b = c.getBlue() / 255.;
        double min, max;
        min = Math.min(r, Math.min(g, b));
        max = Math.max(r, Math.max(g, b));
        double v = max;
        double h = 0;
        if (v == 0)
            return (float) h;
        r /= v;
        g /= v;
        b /= v;
        min = Math.min(r, Math.min(g, b));
        max = Math.max(r, Math.max(g, b));
        double s = max - min;
        if (s == 0) {
            h = 0;
            return (float) h;
        }
        r = (r - min) / s;
        g = (g - min) / s;
        b = (b - min) / s;
        min = Math.min(r, Math.min(g, b));
        max = Math.max(r, Math.max(g, b));
        if (max == r) {
            h = 0.0 + (60. / 360.) * (g - b);
            if (h < 0.0)
                h += 1;
        } else if (max == g) {
            h = (120. / 360.) + (60. / 360.) * (b - r);
        } else /* max == b */ {
            h = (240. / 360.) + (60. / 360.) * (r - g);
        }
        return (float) h;
    }
}

Related

1. HslToRgb(float h, float s, float l, float a)
2. HSLtoRGB(float hue, float sat, float lum)
3. hslToRgb(float[] hsl)
4. HSLtoRGB(float[] hsl)
5. hslToRGB(int h, float s, float l)