Looking for a working example of FFT convolution with Intel IPP

Question

Just trying to wrap my head around IPP right now. Does anyone have any working C/C++ code for doing a FFT convolution on an image?

Answer 1

Example from here:

/* Sample C-code snipet for Example 1 using Intel® Integrated Performance Primitives (Intel® IPP): */

/* allocate and initialize specification structures */
ippsFFTInitAlloc_C_32fc(&FFTspec1_p, order, IPP_FFT_DIV_FWD_BY_N, ippAlgHintFast);
ippsFFTGetBufSize_C_32fc(FFTspec1, &BufSize);
Buf1_p = (Ipp8u *) ippsMalloc_32sc(BufSize*sizeof(Ipp8u));

// ...

/* compute in-place FFTs of input sequences*/
ippsFFTFwd_CToC_32fc_I(x_p, FFTspec1_p, Buf1_p);
ippsFFTFwd_CToC_32fc_I(y_p, FFTspec1_p, Buf1_p);

/* perform complex multiplication and inverse FFT*/
ippsMul_32fc( x_p, y_p, o_p, veclength);
ippsFFTInv_CToC_32fc_I(o_p,FFTspec1_p, Buf1_p);

// ...

/* free specification structures */
ippsFFTFree_C_32fc( FFTSpec1_p);
ippsFree(Buf1_p);

Answer 2

I'm also looking into FFT convolution of an image. My enquiry indicates that ipp functions that start with "ipps" are targeted at signal processing. Ipp functions that start with "ippi" are targeted at image processing. For a working example please look at page 597 of

http://download-software.intel.com/sites/products/documentation/doclib/ipp_sa/71/ipp_manual/ippi.pdf