FilterBilateralInit

Initializes the bilateral context structure.

Syntax

IppStatus ippiFilterBilateralInit(IppiFilterBilateralType filter, IppiSize dstRoiSize, int kernelWidthHeight, IppDataType dataType, int numChannels, IppiDistanceMethodType distMethod, Ipp64f valSquareSigma, Ipp64f posSquareSigma, IppiFilterBilateralSpec* pSpec);

Platform-aware function

IppStatus ippiFilterBilateralInit_L(IppiFilterBilateralType filter, IppiSizeL dstRoiSize, IppSizeL kernelWidthHeight, IppDataType dataType, int numChannels, IppiDistanceMethodType distMethod, Ipp64f valSquareSigma, Ipp64f posSquareSigma, IppiFilterBilateralSpec* pSpec);

Threading Layer (TL) function based on the Platform Aware API

IppStatus ippiFilterBilateralInit_LT(IppiFilterBilateralType filter, IppiSizeL dstRoiSize, IppSizeL kernelWidthHeight, IppDataType dataType, int numChannels, IppiDistanceMethodType distMethod, Ipp64f valSquareSigma, Ipp64f posSquareSigma, IppiFilterBilateralSpec_LT* pSpec);

Threading Layer (TL) function based on the Classic API

IppStatus ippiFilterBilateralInit_T(IppiFilterBilateralType filter, IppiSize dstRoiSize, int kernelWidthHeight, IppDataType dataType, int numChannels, IppiDistanceMethodType distMethod, Ipp64f valSquareSigma, Ipp64f posSquareSigma, IppiFilterBilateralSpec_T* pSpec);

Include Files

ippi.h

ippi_l.h

ippi_tl.h

Domain Dependencies

Flavors declared in ippi.h:

Headers: ippcore.h, ippvm.h, ipps.h

Libraries: ippcore.lib, ippvm.lib, ipps.lib

Parameters

filter

Type of the bilateral filter. Possible value is ippiFilterBilateralGauss - Gaussian bilateral filter.

dstRoiSize

Size of the destination ROI in pixels.

kernelWidthHeight

Linear dimension of the square kernel. The value 1 corresponds to the distance between two adjacent pixels.

dataType

Data type of the source and destination images. Possible values are ipp8u, ipp32f, and ipp64f.

numChannels

Number of channels in the images.

distMethod

Method of defining the differences in intensity between pixels. Depending on the number of channels in the image, possible value are:

numChannels value	Possible distMethod values
1	ippDistNormL1
3	ippDistNormL1, ippDistNormL2

valSquareSigma

Square of the range parameter, which controls smoothing based on the differences in intensity between pixels.

posSquareSigma

Square of the spatial parameter, which controls smoothing based on the geometric distance between pixels.

pSpec

Pointer to the bilateral context structure.

Description

This function initializes the bilateral context structure pSpecSize for bilateral filtering. Before using this function, compute the size of the context structure using the FilterBilateralGetBufferSize function.

The kernelWidthHeight parameter specifies the linear dimension of the square filter kernel. The value 1 corresponds to the distance between the centers of two adjacent pixels.

Coefficients of the bilateral filter kernel depend on their positions in the kernel and on the intensity value of the source image pixels lying in the kernel.

The value of the output pixel d is computed by the following formula:

For all indices i and j that fit within the square kernel

where

v_ij is the value (or channel values) of a pixel in the kernel with coordinates i and j
w1_ij=Fun(valSquareSigma, Intensity Distance(v_ij, v₀₀))

The distMethodType parameter specifies the method of defining the differences in intensity between pixels. FilterBilateral functions support two methods: ippDistNormL1, which defines the difference in intensity as the L1-norm, and ippDistNormL2, which defines the difference in intensity as the L2-norm.
w2_ij=Fun(posSquareSigma, Geometric Distance(v_ij, v₀₀)=sqrt(i*i+j*j))

Fun(S, I)=exp(-I*I/2*S)