topic pyramid functions, correct parameter for in Intel® Integrated Performance Primitives

pyramid functions, correct parameter for

cignarellageomind_it — Thu, 28 Apr 2011 17:01:48 GMT

i'm trying to use pyramid functions:PyramidLayerDownInitAlloc,PyramidLayerDown, and having some problems understanding the parameters to pass toPyramidLayerDownInitAlloc to define the kernel.

i'm using the8u_C3R flavour.

for the 3x3 kernel

| 1 | 3 | 1 |

| 3 | 9 | 3 |

| 1 | 3 | 1 |

my code looks like:

///////////////////////////////////////////////////////////////////////////////

Ipp16s myKernel[]={1,3,1};

int kerSize = 3;

Ipp32f reduceRatio = 2;

IppiPyramidDownState_8u_C3R* pyrDef = NULL;

ippError = ippiPyramidLayerDownInitAlloc_8u_C3R( &pyrDef, srcRoiSize, reduceRatio, myKernel, kerSize,IPPI_INTER_LINEAR );

///////////////////////////////////////////////////////////////////////////////

and this seems to work, ( note kerSize is 3 ), is this the correct way?

my problem is i would have a kernel like this:

| 0 | 0 | 0 |

| 0 | 9 | 3 |

| 0 | 3 | 1 |

but if i use the previous code with

Ipp16s myKernel[]={0,3,1};

i got an ippStsSymKernelExpectederror

why can't have that kernel, is that not symmetric separable?

thanks

marco cignarella

pyramid functions, correct parameter for

Chao_Y_Intel — Fri, 29 Apr 2011 03:13:34 GMT

Hi Marco,

{0,3,1} is not symmetric. The function requires and odd length symmetric kernel.

Thanks,
Chao

pyramid functions, correct parameter for

cignarellageomind_it — Fri, 29 Apr 2011 08:23:34 GMT

I see{0,3,1} is not symmetric,

but the matrix

| 0 | 0 | 0 |

| 0 | 9 | 3 |

| 0 | 3 | 1 |

is ( as a matrix ), so i wished it could be accepted , and passed to function by

[bash]Ipp16s	myKernel[]={0,0,0, 0,9,3, 0,3,1};
int	kerSize = 9;[/bash]

pyramid functions, correct parameter for

Chao_Y_Intel — Thu, 05 May 2011 03:08:19 GMT

Hi,

Thanks for the clarification. Currently, the function only accepts the 1D kernel, not 2D data.

Thanks,
Chao