IppiPyramid with 32f

[Ryan2]

Hi.

Unfotunately, all the examples for Optical flow are using 8u images. The problem I'm having is that the IppiPyramid struct contains 8u Image pointers and I'm using 32f images. I found a threadhttp://software.intel.com/en-us/forums/showthread.php?t=68034&o=a&s=lrthat discusses this; however, the answer is not really helpful.

How do I perform optical flow on 32bit images?

[cpp] IppiPyramid *pPyr1; IppiPyramid *pPyr2; IppiOptFlowPyrLK *pOF; ippiPyramidInitAlloc (&pPyr1, num_levels, ROI, rate); ippiPyramidInitAlloc (&pPyr2, num_levels, ROI, rate); IppiPyramidDownState_32f_C1R** pState1 = (IppiPyramidDownState_32f_C1R**)&(pPyr1->pState); IppiPyramidDownState_32f_C1R** pState2 = (IppiPyramidDownState_32f_C1R**)&(pPyr2->pState); Ipp32f** pImg1 = (Ipp32f**)pPyr1->pImage; Ipp32f** pImg2 = (Ipp32f**)pPyr2->pImage; int *pStep1 = pPyr1->pStep; int *pStep2 = pPyr2->pStep; IppiSize *pRoi1 = pPyr1->pRoi; IppiSize *pRoi2 = pPyr2->pRoi; IppHintAlgorithm hint=ippAlgHintFast; int i; int level = pPyr1->level; ippiPyramidLayerDownInitAlloc_32f_C1R(pState1, ROI, rate, pKernel, kerSize, IPPI_INTER_LINEAR); ippiPyramidLayerDownInitAlloc_32f_C1R(pState2, ROI, rate, pKernel, kerSize, IPPI_INTER_LINEAR); pImg1[0] = Img1Ptr; //32f image pImg2[0] = Img2Ptr;//32f image pStep1[0] = Img1StepBytes;//32f image pStep2[0] = Img2StepBytes;//32f image pRoi1[0] = pRoi2[0] = ROI; // error C2440: '=' : cannot convert from 'Ipp32f *' to 'Ipp8u *' for (i = 1; i <= level; i++) { pPyr1->pImage = (Ipp32f*)ippiMalloc_32f_C1(pRoi1.width, pRoi1.height, pStep1 + i * sizeof(Ipp32f)); pPyr2->pImage = (Ipp32f*)ippiMalloc_32f_C1(pRoi2.width, pRoi2.height, pStep2 + i * sizeof(Ipp32f)); ippiPyramidLayerDown_32f_C1R(pImg1[i-1], pStep1[i-1], pRoi1[i-1], pImg1, pStep1, pRoi1, *pState1); ippiPyramidLayerDown_32f_C1R(pImg2[i-1], pStep2[i-1], pRoi2[i-1], pImg2, pStep2, pRoi2, *pState2); }[/cpp]

I've tried to simply cast the pointers to 32f but I'm getting an error. If I just cast that to Ipp8u, the memory location should still be the same which should fix the error. How do I setpStep1?? Would it not be set to 8u spacing byippiPyramidInitAlloc?

[Ryan2]

ippiPyramidLayerDown_32f_C1R(pImg2[i-1], pStep2[i-1], pRoi2[i-1], pImg2, pStep2, pRoi2, *pState2);

This is returning ippStsStepErr = -14, /* Step value is not valid. */

[Ying_H_Intel]

Hi Ryan,

You can refer to the example code in IPP reference manual, which is using ippiRyramid with 32f.
Example14-6 shows how different general pyramids functions can be used to create the Gaussian and Laplacian pyramids: ( I attached it at the end of message).

For example, please note the code i mark as Bold.
1) Regarding "The IppiPyramid contains pointers to 8 bit unsigned Images", Please see the structure,
typedef struct _IppiPyramid {
Ipp8u **pImage;
IppiSize *pRoi;
Ipp64f *pRate;
int *pStep;
Ipp8u *pState;
int level;
} IppiPyramid;

Here the pionteris actually ** pointer. And the cost happen in
Ipp32** pImg1 = (Ipp32f**)pPyr1->pImage;
Ipp32f** pImg2 = (Ipp32f**)pPyr2->pImage;

And then use the pointer array pImg1[] instead of pPyr1->pImage.

for (i = 1; i <= level; i++)
{
pImg1 = ippiMalloc_32f_C1(pRoi1.width, pRoi1.height, pStep1 + i);//(Ipp32f*)
pImg2 = ippiMalloc_32f_C1(pRoi2.width, pRoi2.height, pStep2 + i);//(Ipp32f*)
sts = ippiPyramidLayerDown_32f_C1R(pImg1[i-1], pStep1[i-1], pRoi1[i-1], pImg1, pStep1, pRoi1, *pState1);
sts = ippiPyramidLayerDown_32f_C1R(pImg2[i-1], pStep2[i-1], pRoi2[i-1], pImg2, pStep2, pRoi2, *pState2);
}

Regarding the wrong steps, as pStep1 is a pointer, The address ofpStep1[1]=pStep+1 (not related to imagedatatype)

After change the two place, you will get your code work.

Best Regards,
Ying

Example of Using General Pyramid Functions

The following Example14-6 shows how different general pyramids functions can be used to create the Gaussian and Laplacian pyramids:

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

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

   }

   // build Laplacian pyramid with level layers

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

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

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

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

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

   }

   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);

          ippiFree(lImage[i-1]);

   }

 }

 //  free pyramid structures

 ippiPyramidFree (gPyr);

 ippiPyramidFree (lPyr);

} 

[Ryan2]

Thank you Ying!