Question

I do not know whether Color.RGBtoHSB(r, g, b, hsb) function normalize the r,g,b before converting it to H,S,B or where i can get the java implementation of their built in functions.

Answer 1

Here is the implementation, from Color class source code directly:

public static float[] RGBtoHSB(int r, int g, int b, float[] hsbvals) {
float hue, saturation, brightness;
if (hsbvals == null) {
    hsbvals = new float[3];
}
    int cmax = (r > g) ? r : g;
if (b > cmax) cmax = b;
int cmin = (r < g) ? r : g;
if (b < cmin) cmin = b;

brightness = ((float) cmax) / 255.0f;
if (cmax != 0)
    saturation = ((float) (cmax - cmin)) / ((float) cmax);
else
    saturation = 0;
if (saturation == 0)
    hue = 0;
else {
    float redc = ((float) (cmax - r)) / ((float) (cmax - cmin));
    float greenc = ((float) (cmax - g)) / ((float) (cmax - cmin));
    float bluec = ((float) (cmax - b)) / ((float) (cmax - cmin));
    if (r == cmax)
    hue = bluec - greenc;
    else if (g == cmax)
        hue = 2.0f + redc - bluec;
        else
    hue = 4.0f + greenc - redc;
    hue = hue / 6.0f;
    if (hue < 0)
    hue = hue + 1.0f;
}
hsbvals[0] = hue;
hsbvals[1] = saturation;
hsbvals[2] = brightness;
return hsbvals;
}