opensolaris man page for mlib_imagestddev

mlib_ImageStdDev(3MLIB) 				    mediaLib Library Functions					   mlib_ImageStdDev(3MLIB)

NAME
       mlib_ImageStdDev - image standard deviation

SYNOPSIS
       cc [ flag... ] file... -lmlib [ library... ]
       #include <mlib.h>

       mlib_status mlib_ImageStdDev(mlib_d64 *sdev, const mlib_image *img,
	    const mlib_d64 *mean);

DESCRIPTION
       The mlib_ImageStdDev() function computes the standard deviation for each channel in the source image.

       It uses the following equation:

		       1     w-1 h-1
	 sdev[i] = { ----- * SUM SUM (img[x][y][i] - mean[i])**2 }**0.5
		      w*h    x=0 y=0

       where, in the case of mean == NULL,

		     1	   w-1 h-1
	 mean[i] = ----- * SUM SUM img[x][y][i]
		    w*h    x=0 y=0

PARAMETERS
       The function takes the following arguments:

       sdev    Pointer to standard deviation array, whose size is the number of channels in the source image. sdev[i] contains the standard devia-
	       tion of channel i.

       img     Pointer to input image.

       mean    Pointer to pre-computed mean array for each channel. (If NULL, it will be computed.) mean[i] contains the mean of channel i.

RETURN VALUES
       The function returns MLIB_SUCCESS if successful. Otherwise it returns MLIB_FAILURE.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Committed 		   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       mlib_ImageMean(3MLIB), mlib_ImageMean_Fp(3MLIB), mlib_ImageStdDev_Fp(3MLIB), attributes(5)

SunOS 5.11							    2 Mar 2007						   mlib_ImageStdDev(3MLIB)