Example of Using General Pyramid Functions

Building Gaussian and Laplacian Pyramids  

void UsePyramids(Ipp32f *pSrc, IppiSize srcRoi, int srcStep, Ipp32f *pkernel, int kerSize) {

 float rate = 2.0f;

 IppiPyramid *gPyr; // pointer to Gaussian pyramid structure

 IppiPyramid *lPyr; // pointer to Laplacian pyramid structure

 // allocate pyramid structures

 ippiPyramidInitAlloc (&gPyr, 1000, srcRoi, rate);

 ippiPyramidInitAlloc (&lPyr, 1000, srcRoi, rate);

 {

   int i;

   IppiPyramidDownState_32f_C1R **gState = (IppiPyramidDownState_32f_C1R**)&(gPyr->pState);

   IppiPyramidUpState_32f_C1R **lState = (IppiPyramidUpState_32f_C1R**) &(lPyr->pState);

   Ipp32f **gImage = (Ipp32f**)(gPyr->pImage);

   Ipp32f **lImage = (Ipp32f**)(lPyr->pImage);

   IppiSize *pRoi = gPyr->pRoi;

   int *gStep = gPyr->pStep;

   int *lStep = lPyr->pStep;

   int level = gPyr->level;

   Ipp32f *ptr;

   int step;

   // allocate structures to calculate pyramid layers

   ippiPyramidLayerDownInitAlloc_32f_C1R
                          (gState, srcRoi, rate, pkernel, kerSize, IPPI_INTER_LINEAR);

   ippiPyramidLayerUpInitAlloc_32f_C1R 
                          (lState, srcRoi, rate, pkernel, kerSize, IPPI_INTER_LINEAR);

   // build Gaussian pyramid with level+1 layers

   gImage[0] = pSrc;

   gStep[0] = srcStep;

   for (i=1; i<=level;i++) {

     gImage[i] = ippiMalloc_32f_C1(pRoi[i].width,pRoi[i].height,gStep+i);

     ippiPyramidLayerDown_32f_C1R
                (gImage[i-1], gStep[i-1], pRoi[i-1], gImage[i], gStep[i], pRoi[i], *gState);

   }

   // build Laplacian pyramid with level layers

   ptr = ippiMalloc_32f_C1(srcRoi.width,srcRoi.height,&step);

   for (i=level-1; i>=0; i--) {

     lImage[i] = ippiMalloc_32f_C1(pRoi[i].width,pRoi[i].height,lStep+i);

     ippiPyramidLayerUp_32f_C1R(gImage[i+1], gStep[i+1], pRoi[i+1], ptr, step, pRoi[i], *lState);

     ippiSub_32f_C1R(ptr, step, gImage[i], gStep[i], lImage[i], lStep[i], pRoi[i]);

   }

   ippiFree(ptr);

   ippiPyramidLayerDownFree_32f_C1R(*gState);

   ippiPyramidLayerUpFree_32f_C1R(*lState);

   // use Gaussian and Laplacian pyramids

   // free allocated images

   for (i=1; i<=level; i++) {

          ippiFree(gImage[i]);

          ippiFree(lImage[i-1]);

   }

 }

 //  free pyramid structures

 ippiPyramidFree (gPyr);

 ippiPyramidFree (lPyr);

}