Intel® Integrated Performance Primitives Developer Reference

Developer Reference

  • 2021
  • 01/15/2021
  • Public Content
Contents

FilterMedian

MODIFIED API.
Computes median values for each source vector element.

Syntax

IppStatus ippsFilterMedian_8u(const Ipp8u*
pSrc
, Ipp8u*
pDst
, int
len
, int
maskSize
, const Ipp8u*
pDlySrc
, Ipp8u*
pDlyDst
, Ipp8u*
pBuffer
);
IppStatus ippsFilterMedian_16s(const Ipp16s*
pSrc
, Ipp16s*
pDst
, int
len
, int
maskSize
, const Ipp16s*
pDlySrc
, Ipp16s*
pDlyDst
, Ipp8u*
pBuffer
);
IppStatus ippsFilterMedian_32s(const Ipp32s*
pSrc
, Ipp32s*
pDst
, int
len
, int
maskSize
, const Ipp32s*
pDlySrc
, Ipp32s*
pDlyDst
, Ipp8u*
pBuffer
);
IppStatus ippsFilterMedian_32f(const Ipp32f*
pSrc
, Ipp32f*
pDst
, int
len
, int
maskSize
, const Ipp32f*
pDlySrc
, Ipp32f*
pDlyDst
, Ipp8u*
pBuffer
);
IppStatus ippsFilterMedian_64f(const Ipp64f*
pSrc
, Ipp64f*
pDst
, int
len
, int
maskSize
, const Ipp64f*
pDlySrc
, Ipp64f*
pDlyDst
, Ipp8u*
pBuffer
);
IppStatus ippsFilterMedian_8u_I(Ipp8u*
pSrcDst
, int
len
, int
maskSize
, const Ipp8u*
pDlySrc
, Ipp8u*
pDlyDst
, Ipp8u*
pBuffer
);
IppStatus ippsFilterMedian_16s_I(Ipp16s*
pSrcDst
, int
len
, int
maskSize
, const Ipp16s*
pDlySrc
, Ipp16s*
pDlyDst
, Ipp8u*
pBuffer
);
IppStatus ippsFilterMedian_32s_I(Ipp32s*
pSrcDst
, int
len
, int
maskSize
, const Ipp32s*
pDlySrc
, Ipp32s*
pDlyDst
, Ipp8u*
pBuffer
);
IppStatus ippsFilterMedian_32f_I(Ipp32f*
pSrcDst
, int
len
, int
maskSize
, const Ipp32f*
pDlySrc
, Ipp32f*
pDlyDst
, Ipp8u*
pBuffer
);
IppStatus ippsFilterMedian_64f_I(Ipp64f*
pSrcDst
, int
len
, int
maskSize
, const Ipp64f*
pDlySrc
, Ipp64f*
pDlyDst
, Ipp8u*
pBuffer
);
Include Files
ipps.h
Domain Dependencies
Headers:
ippcore.h
,
ippvm.h
Libraries:
ippcore.lib
,
ippvm.lib
Parameters
pSrcDst
Pointer to the source and destination vector (for the in-place operation).
pSrc
Pointer to the source vector.
pDst
Pointer to the destination vector.
len
Number of elements in the vector.
maskSize
Median mask size, must be a positive integer. If an even value is specified, the function subtracts 1 and uses the odd value of the filter mask for median filtering.
pDlySrc
Pointer to the array containing values for the source delay lines.
pDlyDst
Pointer to the array containing values for the destination delay lines.
pBuffer
Pointer to the work buffer. To compute the size of the buffer, use the FilterMedianGetBufferSize function.
Description
The API of this function has been modified in Intel IPP 9.0 release.
This function computes median values for each element of the source vector
pSrc
 or
pSrcDst
, and stores the result in
pDst
 or
pSrcDst
, respectively.
The values for non-existent elements are stored in
pDlySrc
 (if it is not NULL). The last (
maskSize
-1) elements of vectors are stored in
pDlyDst
 (if it is not NULL). For example, if
maskSize
 is equal to 3, then:
pDst[0] = median(pDlySrc[0], pDlySrc[1], pSrc[0]);
pDst[1] = median(pDlySrc[1], pSrc[0], pSrc[1]);
pDst[2] = median(pSrc[0], pSrc[1], pSrc[2]);
...
pDlyDst[0] = pSrc[len-2];
pDlyDst[1] = pSrc[len-1]
If
pDlySrc
 is NULL, the value of a non-existent element is equal to the value of the first vector element:
pDst[0] = median(pSrc[0], pSrc[0], pSrc[0]);
pDst[1] = median(pSrc[0], pSrc[0], pSrc[1]);
pDst[2] = median(pSrc[0], pSrc[1], pSrc[2]);
...
If
pDlyDst
 is NULL, the operation of storing the last (
maskSize
-1) elements of vectors is not performed.
Return Values
ippStsNoErr
Indicates no error.
ippStsNullPtrErr
Indicates an error when one of the
pSrcDst
,
pSrc
,
pDst
,
pBuffer
 pointers is
NULL
.
ippStsSizeErr
Indicates an error when
len
 is less than or equal to 0.
ippStsEvenMedianMaskSize
Indicates a warning when the median mask length is even.

Example

The example below illustrates using
ippsFilterMedian_16s_I
 for single-rate filtering.
void median(void) {
      Ipp16s x[8] = {1,2,127,4,5,0,7,8};
      IppStatus status = ippsFilterMedian_16s_I(x, 8, 3);
      printf_16s(“median =”, x,8, status); 
}
Output:
    median =  1 1 2 4 5 4 5 7 
Matlab* Analog: 
    >> x = [1 2 127 4 5 0 7 8]; medfilt1(x)

Product and Performance Information

1

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