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L_ApplyMathLogicBitmap

Summary

Performs specific mathematical or logical operations on the colors of a bitmap.

Syntax

#include "l_bitmap.h"

L_LTIMGCLR_API L_INT L_ApplyMathLogicBitmap(pBitmap, nFactor, uFlags)

Parameters

pBITMAPHANDLE pBitmap

Pointer to the bitmap handle that references the resulting bitmap on which the effect is applied.

L_INT nFactor

Mathematical or logical operation factor.

L_UINT uFlags

Flags that indicate the channel that will be used, the treatment of the input pixel values, the mathematical operation, and the treatment of the output pixel values. Use a bitwise OR ( | ) to specify one flag from each group. Refer to Flags for the L_ApplyMathLogicBitmap * Function for the list of flags.

Returns

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

Comments

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.

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

Calculating Master Channel Values

In order to speed up widely used image processing filters in LEADTOOLS, the grayscale value (master channel) of a colored image is calculated using the following formulas:

#define CalcGrayValue(r, g, b) ((L_UCHAR)(((L_UCHAR) (((2 * (L_UINT) (r)) + (5 * (L_UINT) (g)) + (L_UINT) (b) + 4) / 8)))) 
#define CalcGrayValue16(r, g, b) ((L_UINT16) (((2 * (L_UINT32) (r)) + (5 * (L_UINT32) (g)) + (L_UINT32) (b) + 4) / 8)) 
#define CalcGrayValue32(r, g, b) ((L_UINT32) (((2 * (L_UINT32) (r)) + (5 * (L_UINT32) (g)) + (L_UINT32) (b) + 4) / 8))

Apply Mathematical Logic Function - Before

Apply Mathematical Logic Function - After

View additional platform support for this Apply Mathematical Logic 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 the colors using a factor of 1.51

L_INT ApplyMathLogicBitmapExample(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("NaturalFruits.jpg")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   /* Multiply the colors of the bitmap using a factor of 1.51 */ 
   nRet = L_ApplyMathLogicBitmap(&LeadBitmap, 151, AML_OP_MUL | CHANNEL_MASTER | AML_VALUE_NOP | AML_RES_NOP); 
   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; 
}