#include "ltwrappr.h"

virtual L_INT LBitmap::ApplyMathLogic(nFactor, uFlags)

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


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 LBitmap::ApplyMathLogic* Function for the list of flags.


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


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 only in the Document/Medical 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 LBase::EnableStatusCallback.

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)) 

Required DLLs and Libraries


Win32, x64.

See Also




L_INT LBitmap__ApplyMathLogicExample(LBitmap *pLeadBitmap)  
   /* This example multiplies the colors using a factor of 1.51 */ 
   /* Multiply the colors of the bitmap using a factor of 1.51 */ 
   return pLeadBitmap->ApplyMathLogic(151, AML_OP_MUL| CHANNEL_MASTER| AML_VALUE_NOP| AML_RES_NOP);  
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