#include "ltimgkrn.h"

L_LTIMGKRN_API L_INT L_ImgKrnSignalToNoiseRatio(bitmap, ratio)

BITMAPHANDLE *bitmap; pointer to the bitmap handle
L_DOUBLE *ratio; Signal-To-Noise-Ratio amount

Finds the signal-to-noise-ratio (SNR) in an image.

Parameter Description
bitmap Pointer to the bitmap handle referencing the bitmap to be measured.
ratio Pointer to a variable to be updated with the SNR amount.


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


Calculates the SNR and updates the value of ratio with the 10*log10 of the real ratio. This value gives an indication of the homogeneity of adjacent pixels in an image.

Required DLLs and Libraries

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.


Win32, x64, Linux.

Note: All functions with the L_ImgKrn prefix modify the underlying properties of the input BITMAPHANDLE, including but not limited to:

To avoid BITMAPHANDLE property fidelity loss, pass a copy of your BITMAPHANDLE to all L_ImgKrn* functions.

See Also

Functions: L_ImgKrnCopyImage, L_ImgKrnCreateImage, L_ImgKrnCropImage, L_ImgKrnDetectDocument, L_ImgKrnDetectGlare, L_ImgKrnFromYUV, L_ImgKrnInvertImage, L_ImgKrnManualPerspectiveCorrection, L_ImgKrnRotateFlipImage

Raster Image Functions: Image Analysis


This example loads a bitmap and finds the signal-to-noise-ratio.

L_INT KrnSignalToNoiseRatioExample(L_VOID) 
   L_INT ret; 
   BITMAPHANDLE bitmap;   /* Bitmap handle to hold the loaded image. */ 
   L_DOUBLE snr; 
   /* Load the bitmap */ 
   ret = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("cannon.jpg")), &bitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if (ret != SUCCESS) 
      return ret; 
   /* Apply L_ImgKrnSignalToNoiseRatio and find S/N ratio*/ 
   ret = L_ImgKrnSignalToNoiseRatio(&bitmap, &snr); 
   return ret; 

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