Color Reduction (Scaling down the number of bits)

There are many functions to dither images to 8, 4 or 1 bit per pixel. The differences between color reduction functions are the different error-diffusion algorithms.

Available Functions/Methods:

• DitherFS4

• DitherJJN

• DitherSmooth

• DitherSharp

• DitherStucki

• DitherBurkes

• DitherSierra

• DitherSA.

The DitherOrdered function always dithers to monochrome (1 bit).

Use the Convert32BitDIBTo24Bit function (method) for converting 32 bit per pixel images to 24 bit per pixel.

[C++]

/* Color Reduction*/

#include “BiImage.h”

HDIB hDibNew;

/* 1. parameter: Handle of the DIB to dither

   2. parameter: Dithering to 8 bit */

hDibNew = DitherFS4(hDib, 8);

if (!hDibNew)

{

            // Error

}

[VB]

‘ Color Reduction

Dim hDibNew as Long

Dim BIImageObj As Object

Set BIImageObj = CreateObject("BIIMAGE.BIImageCtrl.1")

‘ 1. parameter: Handle of the DIB to dither

‘ 2. parameter: Dithering to 8 bit

hDibnew = BIImageObj.DitherFS4(hDib, 8)

Set BIImageObj = Nothing

If hDibNew = 0 Then

            ‘ Error

End If

[C#]

/* Color Reduction*/

int hDibNew;

/* 1. parameter: Handle of the DIB to dither

   2. parameter: Dithering to 8 bit */

hDibNew = BiImage.DitherFS4(hDib, 8);

if (hDibNew == 0)

{

            // Error

}