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L_MultiplyBitmap

Summary

Increases or decreases the brightness in the bitmap by multiplying the colors in the specified bitmap by a value equal to the uFactor value divided by 100.

Syntax

#include "l_bitmap.h"

L_LTIMGCLR_API L_INT L_MultiplyBitmap(pBitmap, uFactor, uFlags)

Parameters

pBITMAPHANDLE pBitmap

Pointer to the bitmap handle referencing the bitmap to be changed.

L_UINT uFactor

An integer which represents the factor to be used when multiplying image values. The factor used is equal to uFactor/100.

Returns

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

Comments

This function is used to increase or decrease the brightness in the bitmap by multiplying the colors in the specified bitmap by a value equal to the uFactor value divided by 100. For example, if uFactor is 131, the colors in the specified bitmap will be multiplied by 1.31.

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.

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

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 increases or decreases brightness in the 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:

pBitmap->Flags.UseLUT = FALSE; 
L_MultiplyBitmap(pBitmap, 151, 0); 
pBitmap->Flags.UseLUT = TRUE;

Multiply Function - Before

Multiply Function - After

View additional platform support for this Multiply 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 loads a bitmap and multiplies it with 1.51 factor

L_INT MultiplyBitmapExample(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("IMAGE1.CMP")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   /* Multiply the colors of the bitmap with 1.51*/ 
   nRet = L_MultiplyBitmap(&LeadBitmap, 151, 0); 
   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; 
}