Add ColorHSL and ColorYUV.

1 files changed, 146 insertions, 0 deletions

diff --git a/dmagick/ColorYUV.d b/dmagick/ColorYUV.d
new file mode 100644
index 0000000..16bc63a
--- /dev/null
+++ b/dmagick/ColorYUV.d
@@ -0,0 +1,146 @@
+/**
+ * Copyright: Mike Wey 2011
+ * License:   zlib (See accompanying LICENSE file)
+ * Authors:   Mike Wey
+ */
+
+module dmagick.ColorRGB;
+
+import dmagick.Color;
+
+import dmagick.c.magickType;
+import dmagick.c.quantum;
+
+/**
+ * The YUV color format describes a color by using the color components
+ * luminance and chrominance. The luminance component (Y) represents the
+ * brightness information of a color, the chrominance components (U and V)
+ * contain the color differences.
+ * 
+ * The YUV color format was developed for analog TV transmissions to provide
+ * compatibility between black-and-white television and color television:
+ * The luminance component is sufficient for black-and-white TV sets,
+ * whereas color TV sets need the additional chrominance information.
+ */
+class ColorRGB : Color
+{
+	this()
+	{
+		super();
+	}
+
+	/**
+	 * Create a YUV Color from the specified doubles.
+	 * 
+	 * Params:
+	 *     y = The luminance as a value between 0.0 and 1.0
+	 *     u = The U chrominance component as a value between -0.5 and 0.5
+	 *     v = The V chrominance component as a value between -0.5 and 0.5
+	 */
+	this(double y, double u, double v, double opacity = 0)
+	{
+		Quantum red, green, blue;
+
+		convertYUVToRGB(y, u, v, red, green, blue);
+
+		super(red, green, blue, scaleDoubleToQuantum(opacity));
+	}
+
+	/**
+	 * Create a Color from a X11 color specification string
+	 */
+	this(string color)
+	{
+		super(color);
+	}
+
+	/**
+	 * The value for the luminance in the range [0.0 .. 1.0]
+	 */
+	void y(double y)
+	{
+		double oldY, u, v;
+
+		convertRGBToYUV(pixelPacket.red, pixelPacket.green, pixelPacket.blue, oldY, u, v);
+		convertYUVToRGB(y, u, v, pixelPacket.red, pixelPacket.green, pixelPacket.blue);	
+	}
+	///ditto
+	double y()
+	{
+		return 0.299 * scaleQuantumToDouble(pixelPacket.red) +
+		       0.587 * scaleQuantumToDouble(pixelPacket.green) +
+		       0.114 * scaleQuantumToDouble(pixelPacket.blue);
+	}
+
+	/**
+	 * The value for U chrominance component in the range [-0.5 .. 0.5]
+	 */
+	void u(double u)
+	{
+		double y, oldU, v;
+
+		convertRGBToYUV(pixelPacket.red, pixelPacket.green, pixelPacket.blue, y, oldU, v);
+		convertYUVToRGB(y, u, v, pixelPacket.red, pixelPacket.green, pixelPacket.blue);
+	}
+	///ditto
+	double u()
+	{
+		return -0.147 * scaleQuantumToDouble(pixelPacket.red) +
+		       -0.289 * scaleQuantumToDouble(pixelPacket.green) +
+		        0.436 * scaleQuantumToDouble(pixelPacket.blue);
+	}
+
+	/**
+	 * The value for V chrominance component in the range [-0.5 .. 0.5]
+	 */
+	void v(double v)
+	{
+		double y, u, oldV;
+
+		convertRGBToYUV(pixelPacket.red, pixelPacket.green, pixelPacket.blue, y, u, oldV);
+		convertYUVToRGB(y, u, v, pixelPacket.red, pixelPacket.green, pixelPacket.blue);	
+	}
+	///ditto
+	double v()
+	{
+		return  0.615 * scaleQuantumToDouble(pixelPacket.red) +
+		       -0.515 * scaleQuantumToDouble(pixelPacket.green) +
+		       -0.100 * scaleQuantumToDouble(pixelPacket.blue);
+	}
+
+	/**
+	 * Convert an RGB value to a YUV value.
+	 */
+	private void convertRGBToYUV(Quantum red, Quantum green, Quantum blue, ref double y, ref double u, ref double v)
+	{
+		// ⌈Y⌉ ⌈ 0.299  0.587  0.114⌉ ⌈R⌉
+		// |U|=|-0.147 -0.289  0.436|·|G|
+		// ⌊V⌋ ⌊ 0.615 -0.515 -0.100⌋ ⌊B⌋
+
+		double r = scaleQuantumToDouble(red);
+		double g = scaleQuantumToDouble(green);
+		double b = scaleQuantumToDouble(blue);
+
+		y =  0.299*r +  0.587*g +  0.114*b;
+		u = -0.147*r + -0.289*g +  0.436*b;
+		v =  0.615*r + -0.515*g + -0.100*b;
+	}
+
+	/**
+	 * Convert an YUV value to a RGB value.
+	 */
+	private void convertYUVToRGB(double y, double u, double v, ref Quantum red, ref Quantum green, ref Quantum blue)
+	{
+		// ⌈R⌉ ⌈ 1.000  0.000  1.140⌉ ⌈Y⌉
+		// |G|=| 1.000 -0.395 -0.581|·|U|
+		// ⌊B⌋ ⌊ 1.000  2.032  0.000⌋ ⌊V⌋
+
+		double r = 1.000*y +  0.000*u +  1.140*v;
+		double g = 1.000*y + -0.395*u + -0.581*v;
+		double b = 1.000*y +  2.032*u +  0.000*v;
+
+		red   = scaleDoubleToQuantum(r);
+		green = scaleDoubleToQuantum(g);
+		blue  = scaleDoubleToQuantum(b);
+	}
+}