#include "l_bitmap.h"

L_LTIMGCLR_API L_INT L_SwapColors(pBitmap, uFlags)

Swaps the specified color channels.



Pointer to the bitmap handle that references the bitmap in which to swap the specified color channels.

L_UINT32 uFlags

Flag that indicates which color channels to swap. Possible values are:

Value Meaning
SWAP_RG Swap the red and green channels. (Change red to green and green to red.)
SWAP_RB Swap the red and blue channels. (Change red to blue and blue to red.)
SWAP_GB Swap the green and blue channels. (Change green to blue and blue to green.)
SWAP_RGBR Change red to green, green to blue and blue to red.
SWAP_RBGR Change red to blue, blue to green and green to red.


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


This function changes the bitmap data.

This function can process the whole image or a region of the image.

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 in the Document and Medical Imaging 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.

Required DLLs and Libraries


Win32, x64, Linux.

See Also




This example assumes there is a bitmap loaded into Bitmap, which is of type BITMAPHANDLE.

L_INT SwapColorsExample(L_VOID) 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle to hold the loaded image. */ 
   /* Load the bitmap, keeping the bits per pixel of the file */ 
   nRet = L_LoadBitmap (MAKE_IMAGE_PATH(TEXT("cannon.jpg")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
   nRet = L_SwapColors(&LeadBitmap, SWAP_RG); 
   if(nRet !=SUCCESS) 
      return nRet; 
   nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("Result.BMP")), &LeadBitmap, FILE_BMP, 24, 0, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
   //free bitmap  
   return SUCCESS; 

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