Mean_StdDev

Computes the mean and standard deviation of image pixel values.

Syntax

Case 1: Operation on one-channel data

IppStatus ippiMean_StdDev_<mod>(const Ipp<datatype>* pSrc, int srcStep, IppiSize roiSize, Ipp64f* pMean, Ipp64f* pStdDev);

Supported values for mod:

8u_C1R

8s_C1R

16u_C1R

32f_C1R

Case 2: Masked operation on one-channel data

IppStatus ippiMean_StdDev_<mod>(const Ipp<datatype>* pSrc, int srcStep, const Ipp8u* pMask, int maskStep, IppiSize roiSize, Ipp64f* pMean, Ipp64f* pStdDev);

Supported values for mod:

8u_C1MR

8s_C1MR

16u_C1MR

32f_C1MR

Case 3: Operation on multi-channel data

IppStatus ippiMean_StdDev_<mod>(const Ipp<datatype>* pSrc, int srcStep, IppiSize roiSize, int coi, Ipp64f* pMean, Ipp64f* pStdDev);

Supported values for mod:

8u_C3CR

8s_C3CR

16u_C3CR

32f_C3CR

Case 4: Masked operation on multi-channel data

IppStatus ippiMean_StdDev_<mod>(const Ipp<datatype>* pSrc, int srcStep, const Ipp8u* pMask, int maskStep, IppiSize roiSize, int coi, Ipp64f* pMean, Ipp64f* pStdDev);

Supported values for mod:

8u_C3CMR

8s_C3CMR

16u_C3CMR

32f_C3CMR

Parameters

pSrc	Pointer to the source image ROI.
srcStep	Distance in bytes between starts of consecutive lines in the source image.
pMask	Pointer to the mask image.
maskStep	Distance in bytes between starts of consecutive lines in the mask image.
roiSize	Size of the source ROI in pixels
coi	Channel of interest (for color images only); can be 1, 2, or 3.
pMean	Pointer to the computed mean of pixel values.
pStdDev	Pointer to the computed standard deviation of pixel values in the image.

Description

The function ippiMean_StdDev is declared in the ippcv.h file. It operates with ROI (see Regions of Interest in Intel IPP). This function computes the mean and standard deviation of pixel values in the ROI of the source image pSrc. In the mask mode, the computation is done over pixels selected by nonzero mask values. In the multi-channel mode, the mean is computed for a single channel of interest specified by coi. If any of the parameters pMean or pStdDev is not required, the zero pointer is to be passed to the corresponding parameter.

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error or a warning.
ippStsNullPtrErr	Indicates an error when pSrc or pMask pointer is `NULL`.
ippStsSizeErr	Indicates an error condition if roiSize has a field with zero or negative value.
ippStsStepErr	Indicates an error condition if srcStep or maskStep is less than roiSize.width * <pixelSize >.
ippStsNotEvenStepErr	Indicates an error condition if steps for floating-point images cannot be divided by 4.
ippStsCOIErr	Indicates an error when coi is not 1, 2, or 3.