In This Topic ▼

L_SwapColors

Summary

Swaps the specified color channels.

Syntax

#include "l_bitmap.h"

L_LTIMGCLR_API L_INT L_SwapColors(pBitmap, uFlags)

Parameters

pBITMAPHANDLE pBitmap

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.

Returns

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

Comments

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.

Swap Colors Function - Before

Swap Colors Function - After

View additional platform support for this Swap Colors function.

Required DLLs and Libraries

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, Linux.

Example

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 
   if (LeadBitmap.Flags.Allocated) 
      L_FreeBitmap(&LeadBitmap); 
 
   return SUCCESS; 
}