org.jhotdraw.color
Class CIELCHabColorSpace

java.lang.Object
  java.awt.color.ColorSpace
      org.jhotdraw.color.CIELCHabColorSpace

All Implemented Interfaces:

java.io.Serializable, NamedColorSpace

public class CIELCHabColorSpace
extends java.awt.color.ColorSpace
implements NamedColorSpace

The 1976 CIE L*CHa*b* color space (CIELCH).

The L* coordinate of an object is the lightness intensity as measured on a scale from 0 to 100, where 0 represents black and 100 represents white.

The C and H coordinates are projections of the a* and b* colors of the CIE L*a*b* color space into polar coordinates.

 a = C * cos(H)
 b = C * sin(H)
 

Version:

$Id$

Author:

Werner Randelshofer

See Also:

Serialized Form

Field Summary

Fields inherited from class java.awt.color.ColorSpace

CS_CIEXYZ, CS_GRAY, CS_LINEAR_RGB, CS_PYCC, CS_sRGB, TYPE_2CLR, TYPE_3CLR, TYPE_4CLR, TYPE_5CLR, TYPE_6CLR, TYPE_7CLR, TYPE_8CLR, TYPE_9CLR, TYPE_ACLR, TYPE_BCLR, TYPE_CCLR, TYPE_CMY, TYPE_CMYK, TYPE_DCLR, TYPE_ECLR, TYPE_FCLR, TYPE_GRAY, TYPE_HLS, TYPE_HSV, TYPE_Lab, TYPE_Luv, TYPE_RGB, TYPE_XYZ, TYPE_YCbCr, TYPE_Yxy

Constructor Summary

CIELCHabColorSpace()

Method Summary

float[]	fromCIEXYZ(float[] colorvalue) XYT to Lab.
float[]	fromRGB(float[] rgbvalue)
float	getMaxValue(int component)
float	getMinValue(int component)
java.lang.String	getName()
java.lang.String	getName(int component)
boolean	isClampRGBValues()
static void	main(java.lang.String[] arg)
void	setClampRGBValues(boolean b)
float[]	toCIEXYZ(float[] colorvalue) Lab to XYZ.
float[]	toRGB(float[] colorvalue)

Methods inherited from class java.awt.color.ColorSpace

getInstance, getNumComponents, getType, isCS_sRGB

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CIELCHabColorSpace

public CIELCHabColorSpace()

Method Detail

toRGB

public float[] toRGB(float[] colorvalue)

Specified by:

toRGB in class java.awt.color.ColorSpace

fromRGB

public float[] fromRGB(float[] rgbvalue)

Specified by:

fromRGB in class java.awt.color.ColorSpace

toCIEXYZ

public float[] toCIEXYZ(float[] colorvalue)

Lab to XYZ.

 X = xr*Xr;
 Y = yr*Yr;
 Z = zr*Zr;
 

where

 xr = fx^3, if fx^3 > eps
    = (116*fx - 16)/k, if fx^3 <= eps

 yr = ((L+16)/116)^3, if L > k*eps
    = L/k, if L <= k*eps

 zr = fz^3, if fz^3 > eps
    = (116*fz - 16)/k, if fz^3 <= eps

 fx = a/500+fy

 fz = fy - b / 200

 fy = (L+16)/116

 eps = 216/24389
 k = 24389/27
 

Source: http://www.brucelindbloom.com/index.html?Equations.html

Specified by:

toCIEXYZ in class java.awt.color.ColorSpace

Parameters:

colorvalue - Lab color value.

Returns:

CIEXYZ color value.

fromCIEXYZ

public float[] fromCIEXYZ(float[] colorvalue)

XYT to Lab.

 L = 116*fy - 16
 a = 500 * (fx - fy)
 b = 200 * (fy - fz)
 

where

 fx = xr^(1/3), if xr > eps
    = (k*xr + 16) / 116 if xr <= eps

 fy = yr^(1/3), if yr > eps
    = (k*yr + 16) / 116 if yr <= eps

 fz = zr^(1/3), if zr > eps
    = (k*zr + 16) / 116 if zr <= eps

 xr = X / Xr
 yr = Y / Yr
 zr = Z / Zr

 eps = 216/24389
 k = 24389/27
 

Source: http://www.brucelindbloom.com/index.html?Equations.html

Specified by:

fromCIEXYZ in class java.awt.color.ColorSpace

Parameters:

colorvalue - CIEXYZ color value.

Returns:

Lab color value.

getName

public java.lang.String getName()

Specified by:

getName in interface NamedColorSpace

getMinValue

public float getMinValue(int component)

Overrides:

getMinValue in class java.awt.color.ColorSpace

getMaxValue

public float getMaxValue(int component)

Overrides:

getMaxValue in class java.awt.color.ColorSpace

getName

public java.lang.String getName(int component)

Overrides:

getName in class java.awt.color.ColorSpace

setClampRGBValues

public void setClampRGBValues(boolean b)

isClampRGBValues

public boolean isClampRGBValues()

main

public static void main(java.lang.String[] arg)