mlib_ImageStdDev(3MLIB) mediaLib Library Functions mlib_ImageStdDev(3MLIB)NAMEmlib_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
deviation 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 ALSOmlib_ImageMean(3MLIB), mlib_ImageMean_Fp(3MLIB), mlib_ImageStd‐
Dev_Fp(3MLIB), attributes(5)SunOS 5.10 2 Mar 2007 mlib_ImageStdDev(3MLIB)
