Intel® Integrated Performance Primitives Developer Reference

Developer Reference

  • 2021
  • 03/26/2021
  • Public Content
Contents

CrossCorrNorm

Computes a normalized cross-correlation between an image and a template.

Syntax

Case 1: Operating on data with integer output
IppStatus ippiCrossCorrNorm_8u_C1RSfs(const Ipp8u*
pSrc
, int
srcStep
, IppiSize
srcRoiSize
, const Ipp8u*
pTpl
, int
tplStep
, IppiSize
tplRoiSize
, Ipp8u*
pDst
, int
dstStep
, int
scaleFactor
, IppEnum
algType
, Ipp8u*
pBuffer
);
Case 2: Operating on data with floating-point output
IppStatus ippiCrossCorrNorm_<mod>(const Ipp<srcDatatype>*
pSrc
, int
srcStep
, IppiSize
srcRoiSize
, const Ipp<srcDatatype>*
pTpl
, int
tplStep
, IppiSize
tplRoiSize
, Ipp32f*
pDst
, int
dstStep
, IppEnum
algType
, Ipp8u*
pBuffer
);
Supported values for
mod
:
32f_C1R
8u32f_C1R
16u32f_C1R
Case 3: Operating on data with integer output with TL functions
IppStatus ippsCrossCorrNorm_ 8u_C1RSfs_T (const Ipp8u*
pSrc
, int
srcStep
, IppiSize
srcRoiSize
, const Ipp8u*
pTpl
, int
tplStep
, IppiSize
tplRoiSize
, Ipp8u*
pDst
, int
dstStep
, int
scaleFactor
, IppEnum
algType
, Ipp8u*
pBuffer
);
Case 4: Operating on data with floating-point output with TL functions
IppStatus ippsCrossCorrNorm_ <mod>_T (const Ipp<srcDatatype>*
pSrc
, int
srcStep
, IppiSize
srcRoiSize
, const Ipp<srcDatatype>*
pTpl
, int
tplStep
, IppiSize
tplRoiSize
, Ipp32f*
pDst
, int
dstStep
, IppEnum
algType
, Ipp8u*
pBuffer
);
Supported values for
mod
:
32f_C1R
8u32f_C1R
16u32f_C1R
Include Files
ippi.h
Domain Dependencies
Headers:
ippcore.h
,
ippvm.h
,
ipps.h
Libraries:
ippcore.lib
,
ippvm.lib
,
ipps.lib
Parameters
pSrc
Pointer to the source image ROI.
srcStep
Distance, in bytes, between the starting points of consecutive lines in the source image.
srcRoiSize
Size of the source ROI in pixels.
pTpl
Pointer to the template image.
tplStep
Distance, in bytes, between the starting points of consecutive lines in the template image.
tplRoiSize
Size of the template ROI in pixels.
pDst
Pointer to the destination image ROI.
dstStep
Distance, in bytes, between the starting points of consecutive lines in the destination image.
scaleFactor
Scale factor.
algType
Bit-field mask for the algorithm type definition. Possible values are the results of composition of the
IppAlgType
,
IppiROIShape
, and
IppiNormOp
 values.
pBuffer
Pointer to the work buffer.
Description
This function operates with ROI.
Depending on the
IppiNormOp
 value set to the
algType
 parameter, the function calculates the following results:
IppiNormOp
 Value
Result
ippiNormNone
Cross-correlation values
R
tx
(
r,c
)
ippiNorm
Normalized cross-correlation values
ρ
tx
(
r,c
)
ippiNormCoefficient
Normalized correlation coefficients
γ
tx
(
r,c
)
For more information about how each value is calculated, see Image Proximity Measures.
The size of the resulting matrix depends on the
IppiROIShape
 value:
IppiROIShape
 Value
Matrix Size
ippiROIFull
(
W
s
 +
W
t
 - 1)
*
 (
H
s
 +
H
t
 - 1)
ippiROISame
W
s
*
H
s
ippiROIValid
(
W
s
 -
W
t
 + 1)
*
 (
H
s
 -
H
t
 +1)
where
  • W
    s
     ,
    H
    s
     is the width and height of the source image
  • W
    t
     ,
    H
    t
     is the width and height of the template image
Before using this function, you need to compute the size of the work buffer using the
ippiCrossCorrNormGetBufferSize
 function.
Return Values
ippStsNoErr
Indicates no error.
ippStsNullPtrErr
Indicates an error when any of the specified pointers is NULL.
ippStsStepErr
Indicates an error when the value of
srcStep
,
tplStep
, or
dstStep
 is negative, or equal to zero.
ippStsSizeErr
Indicates an error when:
  • the
    srcRoiSize
     or
    tplRoiSize
     is negative, or equal to zero.
  • the value of
    srcRoiSize
     is less than the corresponding value of the
    tplRoiSize
    .
ippStsAlgTypeErr
Indicates an error when:
  • the result of the bitwise AND operation between the
    algType
     and
    ippAlgMask
     differs from the
    ippAlgAuto
    ,
    ippAlgDirect
    , or
    ippAlgFFT
     values.
  • the result of the bitwise AND operation between the
    algType
     and
    ippiROIMask
     differs from the
    ippiROIFull
    ,
    ippiROISame
    , or
    ippiROIValid
     values.
  • the result of the bitwise AND operation between the
    algType
     and
    ippiNormMask
     differs from the
    ippiNormNone
    ,
    ippiNorm
    , or
    ippiNormCoefficient
     values.

Example

The code example below demonstrates how to use the
ippiCrossCorrNormGetBufferSize
 and
ippiCrossCorrNorm
 functions.
IppStatus CrossCorrNormExample()
{
   IppStatus status;
   IppiSize srcRoiSize = {5,4};
   IppiSize tplRoiSize = {3,3};
   IppiSize dstRoiSize = {5,4};// same as src
   Ipp32f pSrc[5*4] = { 1.0f, 2.0f, 1.5f, 4.1f,  3.6f,
                        0.2f, 3.2f, 2.5f, 1.5f, 10.0f,
                        5.0f, 6.8f, 0.5f, 4.1f,  1.1f,
                        7.1f, 4.2f, 2.2f, 8.7f, 10.0f};
   Ipp32f pTpl[3*3] = {2.1f, 3.5f, 7.7f,
                       0.4f, 2.3f, 5.5f,
                       1.4f, 2.8f, 3.1f};
   Ipp32f pDst[5*4];
   int srcStep = 5*sizeof(Ipp32f);
   int tplStep = 3*sizeof(Ipp32f);
   int dstStep = 5*sizeof(Ipp32f);
   IppEnum funCfg = (IppEnum)(ippAlgAuto|ippiROISame|ippiNorm);
   Ipp8u *pBuffer;
   int bufSize;

   status = ippiCrossCorrNormGetBufferSize(srcRoiSize, tplRoiSize, ipp32f, funCfg, &bufSize);
   if ( status != ippStsNoErr ) return status;

   pBuffer = ippsMalloc_8u( bufSize );

   status = ippiCrossCorrNorm_32f_C1R(pSrc, srcStep, srcRoiSize, pTpl, tplStep, tplRoiSize, pDst, dstStep, funCfg, pBuffer);
   printf_2D_32f("pDst", pDst, dstRoiSize);

   ippsFree( pBuffer );
   return status;
}
The result is as follows:
 pDst ->
  0.53 0.54 0.58 0.50 0.30
  0.68 0.62 0.68 0.83 0.38
  0.77 0.55 0.60 0.81 0.42
  0.81 0.46 0.70 0.62 0.24

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.