#include "l_bitmap.h"

L_LTIMGCLR_API L_INT L_MathFunctionBitmap (pBitmap, uMType, uFactor, uFlags)

Re-maps the image colors according to a mathematical function such as: square, log, square root, sine and cosine.



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


Value that represents the function to be applied. Possible values are:

Value Meaning
MF_SQR [0] Square the values.
MF_LOG [1] Take the log of the values.
MF_SQRT [2] Take the square root of the values.
MF_SIN [3] Take the sine of the values.
MF_COS [4] Take the cosine of the values.

L_UINT uFactor

Factor used as an Amplitude factor when squaring, taking the log of or taking the square root of the color values and as a Frequency factor when taking the sine or cosine of the color values. The value of uFactor is divided internally by different amounts, according to the type of the function being used. These amounts are as follows:

If uMType is set to: then the uFactor will be divided by:
MF_SQR 10000 internally
MF_LOG 10 internally
MF_SQRT 10 internally
MF_SIN 100 internally
MF_COS 100 internally

L_UINT32 uFlags

Reserved for future use. Must be 0.


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


This function uses the RGB color space.

This function makes it possible to apply one of five mathematical functions to a bitmaps pixel values: square, square root, log, sine and cosine.

Select the mathematical operation to be performed on each pixels values with the uMType parameter. The resulting values are multiplied by the factor uFactor. The uFactor parameter can be any value greater than 0. It is divided internally by different amounts, according to the type of the function being used.

If the bitmap has a region, the effect will be applied on the region only.

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.

Required DLLs and Libraries


Win32, x64, Linux.

See Also




This example loads a bitmap and applies a Log Function over the loaded image.

L_INT MathFunctionBitmapExample(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; 
   /* Apply Log Function to this bitmap */ 
   nRet = L_MathFunctionBitmap (&LeadBitmap, MF_LOG, 100, 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  
   return SUCCESS; 

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