local 3d image variance computation More...

IPSDKIPLSTATS_API image::ImagePtr	ipsdk::imaproc::stats::variance3dImg (const image::ImageConstPtr &pInImg3d, const ipUInt32 inHalfKnlSizeX, const ipUInt32 inHalfKnlSizeY, const ipUInt32 inHalfKnlSizeZ)
	wrapper function for Variance filter used on 3d image More...

IPSDKIPLSTATS_API void	ipsdk::imaproc::stats::variance3dImg (const image::ImageConstPtr &pInImg3d, const ipUInt32 inHalfKnlSizeX, const ipUInt32 inHalfKnlSizeY, const ipUInt32 inHalfKnlSizeZ, const image::ImagePtr &pOutImg)
	wrapper function for Variance filter used on 3d image More...

Detailed Description

local 3d image variance computation

This algorithm computes for each pixel of output image associated local variance on a parallelepipedic neighbourhood of input image.

Given an input image $InImg$ and parallelepipedic kernel half sizes $ N_x = InHalfKnlSizeX$ , $ N_y = InHalfKnlSizeY $ and $ N_z = InHalfKnlSizeZ $ , output image values are given by :

$OutImg[x, y, z] = \dfrac{1}{(2 N_z + 1)(2 N_y + 1)(2 N_x + 1)} \sum_{o_{z}=-N_z}^{N_z}{\sum_{o_{y}=-N_y}^{N_y}{\sum_{o_{x}=N_x}^{N_x}{(InImg[x, y, z]-\bar{M}[x, y, z])^2}}}$

where

$\bar{M}[x, y, z] = \dfrac{1}{(2 N_z + 1)(2 N_y + 1)(2 N_x + 1)}\sum_{o_{z}=-N_z}^{N_z}{\sum_{o_{y}=-N_y}^{N_y}{\sum_{o_{x}=N_x}^{N_x}{InImg[x, y, z]}}}$

See also: http://en.wikipedia.org/wiki/Variance

Here is an example of a Variance computation applied on a 8 bits grey level image with $InHalfKnlSizeX = InHalfKnlSizeY = InHalfKnlSizeZ = 7$ :

Attributes description

Attribute description for algorithm :

Name	ToolTip	Default Initializer
ipsdk::imaproc::attr::InImg3d	[Input] 3d image for operation	X
ipsdk::imaproc::attr::InHalfKnlSizeX	[Input] half kernel size along X axis for operation	X
ipsdk::imaproc::attr::InHalfKnlSizeY	[Input] half kernel size along Y axis for operation	X
ipsdk::imaproc::attr::InHalfKnlSizeZ	[Input] half kernel size along Z axis for operation	X
ipsdk::imaproc::attr::OutRealImg	[Output] image for processing operation (data contained in image buffer are reals)	ipsdk::imaproc::duplicateInOut (_pOutRealImg, _pInImg3d, image::eImageBufferType::eIBT_Real32)

Global Rule description

Global rule description for algorithm :
ipsdk::imaproc::matchSize (_pInImg3d,_pOutRealImg)

Example of Python code :

Example imports

import PyIPSDK

import PyIPSDK.IPSDKIPLStats as stats

Code Example

    # opening of input image
    inImg = PyIPSDK.loadTiffImageFile(inputImgPath)
    
    # variance 3d image computation
    outImg = stats.variance3dImg(inImg, 3, 3, 3)

Example of C++ code :

Example informations

Associated library

IPSDKIPLStats

Header file

#include <IPSDKIPL/IPSDKIPLStats/Processor/Variance3dImg/Variance3dImg.h>

Code Example

        // compute variance on input image
        ImagePtr pOutImg = variance3dImg(pInImg, inHalfKnlSizeX, inHalfKnlSizeY, inHalfKnlSizeZ);

See also: Variance3dImgLvl1; Variance3dImgLvl2; Variance3dImgLvl3

Function Documentation

◆ variance3dImg() [1/2]

IPSDKIPLSTATS_API image::ImagePtr ipsdk::imaproc::stats::variance3dImg	(	const image::ImageConstPtr &	pInImg3d,
		const ipUInt32	inHalfKnlSizeX,
		const ipUInt32	inHalfKnlSizeY,
		const ipUInt32	inHalfKnlSizeZ
	)

wrapper function for Variance filter used on 3d image

Exceptions

ipsdk::imaproc::util::IPSDKIPLUtilityException on failure

◆ variance3dImg() [2/2]

IPSDKIPLSTATS_API void ipsdk::imaproc::stats::variance3dImg	(	const image::ImageConstPtr &	pInImg3d,
		const ipUInt32	inHalfKnlSizeX,
		const ipUInt32	inHalfKnlSizeY,
		const ipUInt32	inHalfKnlSizeZ,
		const image::ImagePtr &	pOutImg
	)

wrapper function for Variance filter used on 3d image

Exceptions

ipsdk::imaproc::util::IPSDKIPLUtilityException on failure