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LBitmap::Posterize

Summary

Imposes a poster effect on the class object's bitmap by quantizing the bitmap's colors to a specified number of color levels per plane. For example, two levels means two of red, two of green, and two of blue.

Syntax

#include "ltwrappr.h"

virtual L_INT LBitmap::Posterize(uLevels=4, uFlags = 0)

Parameters

L_UINT uLevels

The number of color levels to use. Valid values are 2 through 64.

L_UINT32 uFlags

Reserved for future use. Must be 0.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

To update a status bar or detect a user interrupt during execution of this function, refer to LBase::EnableStatusCallback.

This function supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available only in the Document/Medical toolkits.

This function does not support 32-bit grayscale images. It returns the error code ERROR_GRAY32_UNSUPPORTED if a 32-bit grayscale image is passed to this function.

This function posterizes image data. If the image has a LUT, the function will work on the LUT, not the image data. If the image has a LUT and you want to work on the image data, set the UseLUT Flag in the BITMAPHANDLE structure to FALSE. Then, after calling the function, reset the UseLUT flag to TRUE as follows:

myBitmap.EnableUseLUT(FALSE); 
myBitmap.Posterize(6); 
myBitmap.EnableUseLUT(TRUE);

Posterize Function - Before

Posterize Function - After

View additional platform support for this Posterize function.

Required DLLs and Libraries

LTDIS
LTFIL
LTIMGCLR
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Win32, x64.

Example

L_INT LBitmap__PosterizeExample() 
{ 
   L_INT nRet; 
   LBitmap LeadBitmap; 
    
   nRet =LeadBitmap.Load(MAKE_IMAGE_PATH(TEXT("image1.cmp")), 0,ORDER_BGR); 
   if(nRet !=SUCCESS) 
      return nRet; 
   nRet =LeadBitmap.Posterize(); 
   if(nRet !=SUCCESS) 
      return nRet; 
   return SUCCESS; 
}