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Rogue Wave Views 5.6

Rogue Wave Views
Foundation Package API Reference Guide

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IlvWUQuantizer Class Reference

WU quantizer class. More...

#include <ilviews/bitmaps/wuquant.h>

Inheritance diagram for IlvWUQuantizer:
IlvQuantizer

Public Member Functions

 IlvWUQuantizer ()
 Constructor.
 
IlvColorMapcomputeColorMap (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 IlvIndexedBitmapDataquantize (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 IlvIndexedBitmapDataremap (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: display

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
dataThe original true color bitmap data.
numcolorsThe requested number of colors.
Returns
The computed colormap. It has at most numcolors colors.

Implements IlvQuantizer.


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