IlvWUQuantizer Class Reference

WU quantizer class. More...

#include <ilviews/bitmaps/wuquant.h>

Inheritance diagram for IlvWUQuantizer:

Public Member Functions
	IlvWUQuantizer ()
	Constructor.
IlvColorMap *	computeColorMap (const IlvBitmapData *data, IlUInt numcolors)
	Computes the colormap from the original true color bitmap data. More...
Public Member Functions inherited from IlvQuantizer
virtual IlBoolean	hasDithering () const
	Returns whether the instance uses Floyd-Steinberg dithering. More...
virtual IlvIndexedBitmapData *	quantize (const IlvBitmapData *data, IlUInt numcols)
	Creates indexed bitmap data from true color bitmap data using the requested number of colors (this number can be ignored by the actual quantizer). The default implementation calls computeColorMap and then remap. More...
virtual IlvIndexedBitmapData *	remap (const IlvBitmapData *data, const IlvColorMap *colormap, IlBoolean fsdither=IlTrue)
	Remaps the true colors to the indexed colors. More...
void	setDithering (IlBoolean dither)
	Sets whether the instance uses Floyd-Steinberg dithering. More...

Detailed Description

WU quantizer class.

Library: xviews or winviews or mviews (mutually exclusive)

This class provides methods to convert true color images to indexed images using a computed colormap. The method used is known as the WU method (see Graphics Gems Vol II), which gives very good results at reasonable speed. This method is the default method used by the Views library to create an IlvBitmap from true color bitmap data on indexed displays.

See also

IlvFixedQuantizer, IlvQuantizer, IlvNetscapeQuantizer, IlvQuickQuantizer

Member Function Documentation

IlvColorMap* IlvWUQuantizer::computeColorMap ( const IlvBitmapData *  data, IlUInt  numcolors  )

virtual

Computes the colormap from the original true color bitmap data.

Parameters

data	The original true color bitmap data.
numcolors	The requested number of colors.

Returns

The computed colormap. It has at most numcolors colors.

Implements IlvQuantizer.