Java Color Brighten brighten(float[] rgb, float luminosity)

Description

Returns a copy of the rgb colour brightened up by the given amount.

License

LGPL

Parameter

Parameter	Description
rgb	The RGB color.
luminosity	The new luminosity amount in [0, 1]

Declaration

public static float[] brighten(float[] rgb, float luminosity) 

Method Source Code

//package com.java2s;
//License from project: LGPL 

public class Main {
    /** //from   w ww . j av a 2s.co m
     * Returns a copy of the rgb colour brightened up by the given amount.
     * @param rgb The RGB color.
     * @param luminosity The new luminosity amount in [0, 1]
     * @return
     */
    public static float[] brighten(float[] rgb, float luminosity) {
        float[] hsl = rgbToHsl(rgb);
        hsl[2] = luminosity;
        return hslToRgb(hsl);
    }

    /**
     * Converts an RGB color value to HSL. Conversion formula
     * adapted from http://en.wikipedia.org/wiki/HSL_color_space.
     * Assumes r, g, and b are contained in the set [0, 255] and
     * returns h, s, and l in the set [0, 1].
     *
     * @param   Number  r       The red color value
     * @param   Number  g       The green color value
     * @param   Number  b       The blue color value
     * @return  Array           The HSL representation
     */
    public static float[] rgbToHsl(float[] rgb) {
        float r, g, b;
        r = rgb[0];
        g = rgb[1];
        b = rgb[2];
        float max = Math.max(r, Math.max(g, b));
        float min = Math.min(r, Math.min(g, b));
        float avg = (max + min) / 2;
        float h = avg, s = avg, l = avg;

        if (max == min) {
            h = s = 0; // achromatic
        } else {
            float d = max - min;
            s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
            if (max == r) {
                h = (g - b) / d + (g < b ? 6 : 0);
            } else if (max == g) {
                h = (b - r) / d + 2;
            } else if (max == b) {
                h = (r - g) / d + 4;
            }
            h /= 6;
        }

        return new float[] { h, s, l };
    }

    /**
     * Converts an HSL color value to RGB. Conversion formula
     * adapted from http://en.wikipedia.org/wiki/HSL_color_space.
     * Assumes h, s, and l are contained in the set [0, 1] and
     * returns r, g, and b in the set [0, 255].
     *
     * @param   Number  h       The hue
     * @param   Number  s       The saturation
     * @param   Number  l       The lightness
     * @return  Array           The RGB representation
     */
    public static float[] hslToRgb(float[] hsl) {
        float r, g, b;
        float h, s, l;
        h = hsl[0];
        s = hsl[1];
        l = hsl[2];

        if (s == 0) {
            r = g = b = l; // achromatic
        } else {

            float q = l < 0.5 ? l * (1 + s) : l + s - l * s;
            float p = 2 * l - q;
            r = hue2rgb(p, q, h + 1 / 3);
            g = hue2rgb(p, q, h);
            b = hue2rgb(p, q, h - 1 / 3);
        }

        return new float[] { r, g, b };
    }

    private static float hue2rgb(float p, float q, float t) {
        if (t < 0)
            t += 1;
        if (t > 1)
            t -= 1;
        if (t < 1 / 6)
            return p + (q - p) * 6 * t;
        if (t < 1 / 2)
            return q;
        if (t < 2 / 3)
            return p + (q - p) * (2 / 3 - t) * 6;
        return p;
    }
}

Related

1. brighten(Color c, double f)
2. brighten(Color color)
3. brighten(final Color color, final double percentage)
4. brighten(final int color)
5. brighten(final int cValue, double colorBrigthnessFactor)
6. brightenColor(Color color, double factor)
7. brighter(Color c)
8. brighter(Color c)
9. brighter(Color c, double factor)