RGB To CMYK

This algorithm converts RGB color model to CMYK color model.

• C#
• VB.Net
• C
• C++
• PHP

									public struct CMYK
{
	private double _c;
	private double _m;
	private double _y;
	private double _k;

	public CMYK(double c, double m, double y, double k)
	{
		this._c = c;
		this._m = m;
		this._y = y;
		this._k = k;
	}

	public double C
	{
		get { return this._c; }
		set { this._c = value; }
	}

	public double M
	{
		get { return this._m; }
		set { this._m = value; }
	}

	public double Y
	{
		get { return this._y; }
		set { this._y = value; }
	}

	public double K
	{
		get { return this._k; }
		set { this._k = value; }
	}

	public bool Equals(CMYK cmyk)
	{
		return (this.C == cmyk.C) && (this.M == cmyk.M) && (this.Y == cmyk.Y) && (this.K == cmyk.K);
	}
}

public struct RGB
{
	private byte _r;
	private byte _g;
	private byte _b;

	public RGB(byte r, byte g, byte b)
	{
		this._r = r;
		this._g = g;
		this._b = b;
	}

	public byte R
	{
		get { return this._r; }
		set { this._r = value; }
	}

	public byte G
	{
		get { return this._g; }
		set { this._g = value; }
	}

	public byte B
	{
		get { return this._b; }
		set { this._b = value; }
	}

	public bool Equals(RGB rgb)
	{
		return (this.R == rgb.R) && (this.G == rgb.G) && (this.B == rgb.B);
	}
}

public static CMYK RGBToCMYK(RGB rgb)
{
	double dr = (double)rgb.R / 255;
	double dg = (double)rgb.G / 255;
	double db = (double)rgb.B / 255;
	double k = 1 - Math.Max(Math.Max(dr, dg), db);
	double c = (1 - dr - k) / (1 - k);
	double m = (1 - dg - k) / (1 - k);
	double y = (1 - db - k) / (1 - k);

	return new CMYK(c, m, y, k);
}
								

Example

									RGB data = new RGB(125, 29, 107);
CMYK value = RGBToCMYK(data);
								

Output

									C: 0
M: 0.7679999999999999
Y: 0.14399999999999993
K: 0.50980392156862742