java.awt.color
Class ColorSpace

java.lang.Object
  |
  +--java.awt.color.ColorSpace

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

ICC_ColorSpace

public abstract class ColorSpace

extends Object

implements Serializable

This abstract class is used to serve as a color space tag to identify the specific color space of a Color object or, via a ColorModel object, of an Image, a BufferedImage, or a GraphicsDevice. It contains methods that transform Colors in a specific color space to/from sRGB and to/from a well-defined CIEXYZ color space.

Several variables are defined for purposes of referring to color space types (e.g. TYPE_RGB, TYPE_XYZ, etc.) and to refer to specific color spaces (e.g. CS_sRGB and CS_CIEXYZ). sRGB is a proposed standard RGB color space. For more information, see http://www.w3.org/pub/WWW/Graphics/Color/sRGB.html .

The purpose of the methods to transform to/from the well-defined CIEXYZ color space is to support conversions between any two color spaces at a reasonably high degree of accuracy. It is expected that particular implementations of subclasses of ColorSpace (e.g. ICC_ColorSpace) will support high performance conversion based on underlying platform color management systems.

The CS_CIEXYZ space used by the toCIEXYZ/fromCIEXYZ methods can be described as follows:

      CIEXYZ
      viewing illuminance: 200 lux
      viewing white point: CIE D50
      media white point: "that of a perfectly reflecting diffuser" -- D50 
      media black point: 0 lux or 0 Reflectance
      flare: 1 percent
      surround: 20percent of the media white point
      media description: reflection print (i.e., RLAB, Hunt viewing media)
      note: For developers creating an ICC profile for this conversion
            space, the following is applicable.  Use a simple Von Kries
            white point adaptation folded into the 3X3 matrix parameters
            and fold the flare and surround effects into the three
            one-dimensional lookup tables (assuming one uses the minimal
            model for monitors).

See Also:

ICC_ColorSpace, Serialized Form

Field Summary

static int	CS_CIEXYZ The CIEXYZ conversion color space defined above.
static int	CS_GRAY The built-in linear gray scale color space.
static int	CS_LINEAR_RGB A built-in linear RGB color space.
static int	CS_PYCC The Photo YCC conversion color space.
static int	CS_sRGB The sRGB color space defined at http://www.w3.org/pub/WWW/Graphics/Color/sRGB.html .
static int	TYPE_2CLR Generic 2 component color spaces.
static int	TYPE_3CLR Generic 3 component color spaces.
static int	TYPE_4CLR Generic 4 component color spaces.
static int	TYPE_5CLR Generic 5 component color spaces.
static int	TYPE_6CLR Generic 6 component color spaces.
static int	TYPE_7CLR Generic 7 component color spaces.
static int	TYPE_8CLR Generic 8 component color spaces.
static int	TYPE_9CLR Generic 9 component color spaces.
static int	TYPE_ACLR Generic 10 component color spaces.
static int	TYPE_BCLR Generic 11 component color spaces.
static int	TYPE_CCLR Generic 12 component color spaces.
static int	TYPE_CMY Any of the family of CMY color spaces.
static int	TYPE_CMYK Any of the family of CMYK color spaces.
static int	TYPE_DCLR Generic 13 component color spaces.
static int	TYPE_ECLR Generic 14 component color spaces.
static int	TYPE_FCLR Generic 15 component color spaces.
static int	TYPE_GRAY Any of the family of GRAY color spaces.
static int	TYPE_HLS Any of the family of HLS color spaces.
static int	TYPE_HSV Any of the family of HSV color spaces.
static int	TYPE_Lab Any of the family of Lab color spaces.
static int	TYPE_Luv Any of the family of Luv color spaces.
static int	TYPE_RGB Any of the family of RGB color spaces.
static int	TYPE_XYZ Any of the family of XYZ color spaces.
static int	TYPE_YCbCr Any of the family of YCbCr color spaces.
static int	TYPE_Yxy Any of the family of Yxy color spaces.

Constructor Summary

protected

ColorSpace(int type, int numcomponents) Constructs a ColorSpace object given a color space type and the number of components.

Method Summary

abstract float[]	fromCIEXYZ(float[] colorvalue) Transforms a color value assumed to be in the CS_CIEXYZ conversion color space into this ColorSpace.
abstract float[]	fromRGB(float[] rgbvalue) Transforms a color value assumed to be in the default CS_sRGB color space into this ColorSpace.
static ColorSpace	getInstance(int colorspace) Returns a ColorSpace representing one of the specific predefined color spaces.
String	getName(int idx) Returns the name of the component given the component index
int	getNumComponents() Returns the number of components of this ColorSpace.
int	getType() Returns the color space type of this ColorSpace (for example TYPE_RGB, TYPE_XYZ, ...).
boolean	isCS_sRGB() Returns true if the ColorSpace is CS_sRGB.
abstract float[]	toCIEXYZ(float[] colorvalue) Transforms a color value assumed to be in this ColorSpace into the CS_CIEXYZ conversion color space.
abstract float[]	toRGB(float[] colorvalue) Transforms a color value assumed to be in this ColorSpace into a value in the default CS_sRGB color space.

Methods inherited from class java.lang.Object

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

Field Detail

TYPE_XYZ

public static final int TYPE_XYZ

Any of the family of XYZ color spaces.

TYPE_Lab

public static final int TYPE_Lab

Any of the family of Lab color spaces.

TYPE_Luv

public static final int TYPE_Luv

Any of the family of Luv color spaces.

TYPE_YCbCr

public static final int TYPE_YCbCr

Any of the family of YCbCr color spaces.

TYPE_Yxy

public static final int TYPE_Yxy

Any of the family of Yxy color spaces.

TYPE_RGB

public static final int TYPE_RGB

Any of the family of RGB color spaces.

TYPE_GRAY

public static final int TYPE_GRAY

Any of the family of GRAY color spaces.

TYPE_HSV

public static final int TYPE_HSV

Any of the family of HSV color spaces.

TYPE_HLS

public static final int TYPE_HLS

Any of the family of HLS color spaces.

TYPE_CMYK

public static final int TYPE_CMYK

Any of the family of CMYK color spaces.

TYPE_CMY

public static final int TYPE_CMY

Any of the family of CMY color spaces.

TYPE_2CLR

public static final int TYPE_2CLR

Generic 2 component color spaces.

TYPE_3CLR

public static final int TYPE_3CLR

Generic 3 component color spaces.

TYPE_4CLR

public static final int TYPE_4CLR

Generic 4 component color spaces.

TYPE_5CLR

public static final int TYPE_5CLR

Generic 5 component color spaces.

TYPE_6CLR

public static final int TYPE_6CLR

Generic 6 component color spaces.

TYPE_7CLR

public static final int TYPE_7CLR

Generic 7 component color spaces.

TYPE_8CLR

public static final int TYPE_8CLR

Generic 8 component color spaces.

TYPE_9CLR

public static final int TYPE_9CLR

Generic 9 component color spaces.

TYPE_ACLR

public static final int TYPE_ACLR

Generic 10 component color spaces.

TYPE_BCLR

public static final int TYPE_BCLR

Generic 11 component color spaces.

TYPE_CCLR

public static final int TYPE_CCLR

Generic 12 component color spaces.

TYPE_DCLR

public static final int TYPE_DCLR

Generic 13 component color spaces.

TYPE_ECLR

public static final int TYPE_ECLR

Generic 14 component color spaces.

TYPE_FCLR

public static final int TYPE_FCLR

Generic 15 component color spaces.

CS_sRGB

public static final int CS_sRGB

The sRGB color space defined at http://www.w3.org/pub/WWW/Graphics/Color/sRGB.html .

CS_LINEAR_RGB

public static final int CS_LINEAR_RGB

A built-in linear RGB color space. This space is based on the same RGB primaries as CS_sRGB, but has a linear tone reproduction curve.

CS_CIEXYZ

public static final int CS_CIEXYZ

The CIEXYZ conversion color space defined above.

CS_PYCC

public static final int CS_PYCC

The Photo YCC conversion color space.

CS_GRAY

public static final int CS_GRAY

The built-in linear gray scale color space.

Constructor Detail

ColorSpace

protected ColorSpace(int type,
                     int numcomponents)

Constructs a ColorSpace object given a color space type and the number of components.

Method Detail

getInstance

public static ColorSpace getInstance(int colorspace)

Returns a ColorSpace representing one of the specific predefined color spaces.

Parameters:

colorspace - a specific color space identified by one of the predefined class constants (e.g. CS_sRGB, CS_LINEAR_RGB, CS_CIEXYZ, CS_GRAY, or CS_PYCC)

isCS_sRGB

public boolean isCS_sRGB()

Returns true if the ColorSpace is CS_sRGB.

toRGB

public abstract float[] toRGB(float[] colorvalue)

Transforms a color value assumed to be in this ColorSpace into a value in the default CS_sRGB color space.

This method transforms color values using algorithms designed to produce the best perceptual match between input and output colors. In order to do colorimetric conversion of color values, you should use the toCIEXYZ method of this color space to first convert from the input color space to the CS_CIEXYZ color space, and then use the fromCIEXYZ method of the CS_sRGB color space to convert from CS_CIEXYZ to the output color space. See toCIEXYZ and fromCIEXYZ for further information.

Parameters:

colorvalue - a float array with length of at least the number of components in this ColorSpace

Returns:

a float array of length 3

fromRGB

public abstract float[] fromRGB(float[] rgbvalue)

Transforms a color value assumed to be in the default CS_sRGB color space into this ColorSpace.

This method transforms color values using algorithms designed to produce the best perceptual match between input and output colors. In order to do colorimetric conversion of color values, you should use the toCIEXYZ method of the CS_sRGB color space to first convert from the input color space to the CS_CIEXYZ color space, and then use the fromCIEXYZ method of this color space to convert from CS_CIEXYZ to the output color space. See toCIEXYZ and fromCIEXYZ for further information.

Parameters:

rgbvalue - a float array with length of at least 3

Returns:

a float array with length equal to the number of components in this ColorSpace

toCIEXYZ

public abstract float[] toCIEXYZ(float[] colorvalue)

Transforms a color value assumed to be in this ColorSpace into the CS_CIEXYZ conversion color space.

This method transforms color values using relative colorimetry, as defined by the International Color Consortium standard. This means that the XYZ values returned by this method are represented relative to the D50 white point of the CS_CIEXYZ color space. This representation is useful in a two-step color conversion process in which colors are transformed from an input color space to CS_CIEXYZ and then to an output color space. This representation is not the same as the XYZ values that would be measured from the given color value by a colorimeter. A further transformation is necessary to compute the XYZ values that would be measured using current CIE recommended practices. See the toCIEXYZ method of ICC_ColorSpace for further information.

Parameters:

colorvalue - a float array with length of at least the number of components in this ColorSpace

Returns:

a float array of length 3

fromCIEXYZ

public abstract float[] fromCIEXYZ(float[] colorvalue)

Transforms a color value assumed to be in the CS_CIEXYZ conversion color space into this ColorSpace.

This method transforms color values using relative colorimetry, as defined by the International Color Consortium standard. This means that the XYZ argument values taken by this method are represented relative to the D50 white point of the CS_CIEXYZ color space. This representation is useful in a two-step color conversion process in which colors are transformed from an input color space to CS_CIEXYZ and then to an output color space. The color values returned by this method are not those that would produce the XYZ value passed to the method when measured by a colorimeter. If you have XYZ values corresponding to measurements made using current CIE recommended practices, they must be converted to D50 relative values before being passed to this method. See the fromCIEXYZ method of ICC_ColorSpace for further information.

Parameters:

colorvalue - a float array with length of at least 3

Returns:

a float array with length equal to the number of components in this ColorSpace

getType

public int getType()

Returns the color space type of this ColorSpace (for example TYPE_RGB, TYPE_XYZ, ...). The type defines the number of components of the color space and the interpretation, e.g. TYPE_RGB identifies a color space with three components - red, green, and blue. It does not define the particular color characteristics of the space, e.g. the chromaticities of the primaries.

getNumComponents

public int getNumComponents()

Returns the number of components of this ColorSpace.

getName

public String getName(int idx)

Returns the name of the component given the component index