/*******************************************************************************
* Copyright 2015-2018 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.
*******************************************************************************/
// The code example below illustrates how the horizontal edges of an image can be detected.
// implemented with Intel(R) Integrated Primitives (Intel(R) IPP) functions:
// ippiSet_32f_C1R
// ippiAddC_32f_C1IR
// ippiCopy_32f_C1R
// ippiFFTGetSize_R_32f
// ippiFFTInit_R_32f
// ippiFFTFwd_RToPack_32f_C1R
// ippiMulPack_32f_C1R
// ippiFFTInv_PackToR_32f_C1R
#include <stdio.h>
#include "ipp.h"
/* 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;
IppiFFTSpec_R_32f *pSpec = NULL; /* Pointer to FFT spec structure */
Ipp32f pSrc[64], pFlt[64], pDst[64]; /* Pointers to source/filter/destination images */
Ipp32f pSrcFr[64], pFltFr[64], pDstFr[64]; /* Pointers to source/filter/destination images into the frequency domain */
Ipp8u *pMemInit = NULL, *pBuffer = NULL; /* Pointer to the work buffers */
int sizeSpec = 0, sizeInit = 0, sizeBuf = 0; /* size of FFT spec structure, Init and work buffers */
const IppiSize roiSize8x8 = { 8, 8 }, roiSize3x3 = { 3, 3 }; /* image and filter roi sizes */
const Ipp32f filter[3*3] = {-1,-1,-1, 0,0,0, 1,1,1}; /* filter data */
/* set the image zero */
check_sts( status = ippiSet_32f_C1R( 0, pSrc, 8*sizeof(Ipp32f), roiSize8x8 ) )
/* create unit area in the image */
check_sts( status = ippiAddC_32f_C1IR( 1, pSrc+8+1, 8*sizeof(Ipp32f), roiSize3x3 ) )
/* set the filter zero */
check_sts( status = ippiSet_32f_C1R( 0, pFlt, 8*sizeof(Ipp32f), roiSize8x8 ) )
/* copy the filter coefficients */
check_sts( status = ippiCopy_32f_C1R( filter, 3*sizeof(Ipp32f), pFlt, 8*sizeof(Ipp32f), roiSize3x3 ) )
check_sts( status = ippiFFTGetSize_R_32f(3, 3, IPP_FFT_DIV_INV_BY_N, ippAlgHintAccurate,
&sizeSpec, &sizeInit, &sizeBuf) )
/* memory allocation */
pSpec = (IppiFFTSpec_R_32f*) ippMalloc( sizeSpec );
pBuffer = (Ipp8u*) ippMalloc( sizeBuf );
pMemInit = (Ipp8u*) ippMalloc( sizeInit );
check_sts( status = ippiFFTInit_R_32f(3, 3, IPP_FFT_DIV_INV_BY_N, ippAlgHintAccurate, pSpec, pMemInit) )
/* forward FFT transform : the source image is transformed into the frequency domain*/
check_sts( status = ippiFFTFwd_RToPack_32f_C1R( pSrc, 8*sizeof(Ipp32f), pSrcFr, 8*sizeof(Ipp32f), pSpec, pBuffer ) )
/* forward FFT transform: the filter is transformed into the frequency domain */
check_sts( status = ippiFFTFwd_RToPack_32f_C1R( pFlt, 8*sizeof(Ipp32f), pFltFr, 8*sizeof(Ipp32f), pSpec, pBuffer ) )
/* multiplying the packed data */
check_sts( status = ippiMulPack_32f_C1R( pSrcFr, 8*sizeof(Ipp32f), pFltFr, 8*sizeof(Ipp32f), pDstFr, 8*4, roiSize8x8) )
/* inverse FFT transform : the filtered data is transformed to the time domain */
check_sts( status = ippiFFTInv_PackToR_32f_C1R( pDstFr, 8*sizeof(Ipp32f), pDst, 8*sizeof(Ipp32f), pSpec, pBuffer ) )
EXIT_MAIN
ippFree( pMemInit );
ippFree( pSpec );
ippFree( pBuffer );
printf("Exit status %d (%s)\n", (int)status, ippGetStatusString(status));
return (int)status;
}