LBitmapBase::ClearNegativePixels

#include "ltwrappr.h"

virtual L_INT LBitmapBase::ClearNegativePixels(void)

Sets all of the class object's bitmap pixels with negative color values to 0.

Returns

SUCCESS

The function was successful.

< 1

An error occurred. Refer to Return Codes.

Comments

If ELO_SIGNED flag has been set using LOADFILEOPTION, before a file is loaded, the bitmap may contain negative pixel values and LEADTOOLS will paint/process the image incorrectly. In order to use this bitmap correctly, you must call LBitmapBase::ClearNegativePixels. If the ELO_SIGNED flag has not been set, all negative pixels are cleared internally, during the load process. Since some TIFF files are saved with negative values for pixel colors, you should call LBitmapBase::ClearNegativePixels if, after loading a bitmap, LBitmapBase::IsPixelsSigned returns TRUE.

LBitmapBase::ClearNegativePixels does nothing if LBitmapBase::IsPixelsSigned returns FALSE.

PROGRAMMING TIP: Call LBitmapBase::ClearNegativePixels right after LBitmapBase::Load or LFile::Load.

Required DLLs and Libraries

LTDIS
LTFIL

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.

See Also

Functions:

LBitmapBase::IsPixelsSigned, LBitmapBase::Clear, LBitmapBase::Load, LFile::Load, Class Members

Topics

Raster Image Functions: Getting and Setting Pixel Values

Example

L_INT LBitmapBase__ClearNegativePixelsExample() 
{ 
   L_INT nRet; 
   LBitmapBase MyBitmap; 
 
   MyBitmap.SetFileName(MAKE_IMAGE_PATH(TEXT("signed-test.tif")));  
   nRet =MyBitmap.Load(); 
   if(nRet !=SUCCESS) 
      return nRet; 
 
   if(MyBitmap.IsPixelsSigned()) 
   { 
      nRet =MyBitmap.ClearNegativePixels(); 
      if(nRet !=SUCCESS) 
         return nRet; 
   } 
   else 
      return FAILURE;  
 
   return SUCCESS; 
} 
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LEADTOOLS Raster Imaging C++ Class Library Help