FilterGaussian

Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference

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ID 790148

Date 3/22/2024

Version

Public

Visible to Intel only — GUID: GUID-B0DD6A7F-8FF3-4B9C-81CA-5BBA4E27B4D2

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FilterGaussian

Performs Gaussian filtering of an image with user-defined borders.

Syntax

Case 1: Operating on one-channel data

IppStatus ippiFilterGaussian_<mod>(const Ipp<datatype>* pSrc, int srcStep, Ipp<datatype>* pDst, int dstStep, IppiSize roiSize, IppiBorderType borderType, const Ipp<datatype> borderValue[1], IppFilterGaussianSpec* pSpec, Ipp8u* pBuffer);

Supported values for mod:

8u_C1R

16u_C1R

16s_C1R

32f_C1R

Case 2: Operating on multi-channel data

IppStatus ippiFilterGaussian_<mod>(const Ipp<datatype>* pSrc, int srcStep, Ipp<datatype>* pDst, int dstStep, IppiSize roiSize, IppiBorderType borderType, const Ipp<datatype> borderValue[3], IppFilterGaussianSpec* pSpec, Ipp8u* pBuffer);

Supported values for mod:

8u_C3R

16u_C3R

16s_C3R

32f_C3R

Case 3: Operating on one-channel data with platform-aware functions

IppStatus ippiFilterGaussian_<mod>(const Ipp<datatype>* pSrc, IppSizeL srcStep, Ipp<datatype>* pDst, IppSizeL dstStep, IppiSizeL roiSize, IppiBorderType borderType, const Ipp<datatype> borderValue[1], IppFilterGaussianSpec* pSpec, Ipp8u* pBuffer);

Supported values for mod:

8u_C1R_L

16u_C1R_L

16s_C1R_L

32f_C1R_L

Case 4: Operating on multi-channel data with platform-aware functions

IppStatus ippiFilterGaussian_<mod>(const Ipp<datatype>* pSrc, IppSizeL srcStep, Ipp<datatype>* pDst, IppSizeL dstStep, IppiSizeL roiSize, IppiBorderType borderType, const Ipp<datatype> borderValue[3], IppFilterGaussianSpec* pSpec, Ipp8u* pBuffer);

Supported values for mod:

8u_C3R_L

16u_C3R_L

16s_C3R_L

32f_C3R_L

Include Files

ippcv.h

ippcv_l.h

Domain Dependencies

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

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

Parameters

pSrc	Pointer to the source image ROI.
srcStep	Distance, in bytes, between the starting points of consecutive lines in the source image.
pDst	Pointer to the destination image ROI.
dstStep	Distance, in bytes, between the starting points of consecutive lines in the destination image.
roiSize	Size of the source and destination image ROI, in pixels.
borderType	One of the supported border types.
borderValue	Constant value to assign to pixels of the constant border. This parameter is applicable only to the ippBorderConst border type.
pSpec	Pointer to the Gaussian specification structure.
pBuffer	Pointer to the work buffer.

Description

This function operates with ROI (see Regions of Interest in Intel IPP).

These functions apply the Gaussian filter to the source image ROI pSrc. The kernel of the Gaussian filter is the matrix of size kernelSizexkernelSize with the standard deviation sigma. The values of the Gaussian kernel elements are computed by the FilterGaussianInit function. Elements of the kernel are normalized. The anchor cell is the center of the kernel.

Before using the ippiFilterGaussian function, compute the size of the Gaussian specification structure using the FilterGaussianGetSpecSize function and the external buffer using the FilterGaussianGetBufferSize function and initialize the structure using the FilterGaussianInit function.

Return Values

ippStsNoErr	Indicates no error.
ippStsNullPtrErr	Indicates an error when one of the specified pointers is NULL.
ippStsSizeErr	Indicates an error when roiSize has a field with a zero or negative value.
ippStsStepErr	Indicates an error when srcStep or dstStep is less than roiSize.width*<pixelSize>.
ippStsNotEvenStepErr	Indicates an error when one of the step values is not divisible by `sizeof(Ipp<dataType>)`.
ippStsBorderErr	Indicates an error when borderType has an illegal value.
ippStsBadArgErr	Indicates an error when kernelSize is even, or less than 3.

Example

/*******************************************************************************
* Copyright 2022 Intel Corporation.
*
*
* This software and the related documents are Intel copyrighted materials, and your use of them is governed by
* the express license under which they were provided to you ('License'). Unless the License provides otherwise,
* you may not use, modify, copy, publish, distribute, disclose or transmit this software or the related
* documents without Intel's prior written permission.
* This software and the related documents are provided as is, with no express or implied warranties, other than
* those that are expressly stated in the License.
*******************************************************************************/

//   A simple example of performing a filtering an image using a general integer rectangular kernel
// implemented with Intel(R) Integrated Performance Primitives (Intel(R) IPP) functions:
//     ippiImageJaehne_32f_C1R
//     ippiFilterGaussianGetSpecSize_L
//     ippiFilterGaussianInit_L
//     ippiFilterGaussianGetBufferSize_L
//     ippiFilterGaussian_32f_C1R_L


#include <stdio.h>
#include "ipp.h"

#define WIDTH  128  /* image width */
#define HEIGHT  64  /* image height */

/* Next two defines are created to simplify code reading and understanding */
#define EXIT_MAIN exitLine:                                  /* Label for Exit */
#define check_sts(st) if((st) != ippStsNoErr) goto exitLine; /* Go to Exit if Intel(R) IPP function returned status different from ippStsNoErr */

/* Results of ippMalloc() are not validated because Intel(R) IPP functions perform bad arguments check and will return an appropriate status  */

int main(void)
{
    IppStatus status = ippStsNoErr;
    Ipp32f* pSrc = NULL, * pDst = NULL;     /* Pointers to source/destination images */
    IppSizeL srcStep = 0, dstStep = 0;      /* Steps, in bytes, through the source/destination images */
    IppiSizeL roiSizeL = { WIDTH, HEIGHT }; /* Size of source/destination ROI in pixels */
    IppiSize roiSize = { WIDTH, HEIGHT };   /* Size of source/destination ROI in pixels - for ImageJaehne only */
    int kernelSize = 3;
    Ipp32f sigma = 0.35f;
    Ipp8u* pBuffer = NULL;                 /* Pointer to the work buffer */
    Ipp8u* pInitBuf = NULL;                /* Pointer to the Init buffer */
    IppFilterGaussianSpec* pSpec = NULL;   /* context structure */
    IppSizeL iTmpBufSize = 0, iSpecSize = 0, iInitBufSize = 0;    /* Common work buffer size */
    IppiBorderType borderType = ippBorderRepl;
    Ipp32f borderValue = 0;
    int numChannels = 1;

    pSrc = ippiMalloc_32f_C1_L(roiSize.width, roiSize.height, &srcStep);
    pDst = ippiMalloc_32f_C1_L(roiSize.width, roiSize.height, &dstStep);

    check_sts(status = ippiImageJaehne_32f_C1R(pSrc, (int)srcStep, roiSize)) /* fill source image */

    check_sts(status = ippiFilterGaussianGetSpecSize_L(kernelSize, ipp32f, numChannels,
        &iSpecSize, &iInitBufSize))

    pSpec = (IppFilterGaussianSpec*)ippsMalloc_8u_L(iSpecSize);
    pInitBuf = ippsMalloc_8u_L(iInitBufSize);

    status = ippiFilterGaussianInit_L(roiSizeL, kernelSize, sigma, borderType,
        ipp32f, numChannels, pSpec, pInitBuf);
    ippsFree(pInitBuf);
    check_sts(status)

    check_sts(status = ippiFilterGaussianGetBufferSize_L(roiSizeL, kernelSize, ipp32f, borderType,
        numChannels, &iTmpBufSize))

    pBuffer = ippsMalloc_8u_L(iTmpBufSize);

    check_sts(status = ippiFilterGaussian_32f_C1R_L(pSrc, srcStep, pDst, dstStep, roiSizeL,
        borderType, &borderValue, pSpec, pBuffer))

    EXIT_MAIN
    ippsFree(pBuffer);
    ippsFree(pSpec);
    ippiFree(pSrc);
    ippiFree(pDst);
    printf("Exit status %d (%s)\n", (int)status, ippGetStatusString(status));
    return (int)status;
}

Parent topic: Fixed Filters

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Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference

FilterGaussian

Syntax

Include Files

Domain Dependencies

Parameters

Description

Return Values

Example

See Also