Developer Reference

  • 2020
  • 07/15/2020
  • Public Content
Contents

CannyBorder

Implements Canny algorithm for edge detection.

Syntax

IppStatus ippiCannyBorder_8u_C1R(const Ipp8u*
pSrc
, int
srcStep
, Ipp8u*
pDst
, int
dstStep
, IppiSize
roiSize
, IppiDifferentialKernel
filterType
, IppiMaskSize
mask
, IppiBorderType
borderType
, Ipp8u
borderValue
, Ipp32f
lowThresh
, Ipp32f
highThresh
, IppNormType
norm
, Ipp8u*
pBuffer
);
Include Files
ippcv.h
Domain Dependencies
Headers:
ippcore.h
,
ippvm.h
,
ipps.h
,
ippi.h
Libraries:
ippcore.lib
,
ippvm.lib
,
ipps.lib
,
ippi.lib
Parameters
pSrc
Pointer to the source image.
srcStep
Distance, in bytes, between the starting points of consecutive lines in the source image.
pDst
Pointer to the destination image.
dstStep
Distance, in bytes, between the starting points of consecutive lines in the destination image.
roiSize
Size of the source image ROI in pixels.
filterType
Type of the filter to be applied. Possible values are
ippFilterSobel
and
ippFilterScharr
.
mask
The size of the mask. Possible values are
ippMskSize3x3
and
ippMskSize5x5
for
ippFilterSobel
, and
ippMskSize3x3
for
ippFilterScharr
.
borderType
Type of border. Possible values are:
ippBorderConst
Values of all border pixels are set to constant.
ippBorderRepl
Border is replicated from the edge pixels.
ippBorderInMem
Border is obtained from the source image pixels in memory.
Mixed borders are also supported. They can be obtained by the bitwise operation OR between
ippBorderRepl
and
ippBorderInMemTop
,
ippBorderInMemBottom
,
ippBorderInMemLeft
,
ippBorderInMemRight
.
borderValue
Constant value to assign to pixels of the constant border. This parameter is applicable only to the
ippBorderConst
border type.
lowThresh
Lower threshold for edges detection.
highThresh
Upper threshold for edges detection.
norm
Normalization mode. Possible values are
ippNormL1
and
ippNormL2
.
pBuffer
Pointer to the pre-allocated temporary buffer. To calculate the size of the temporary buffer, use the CannyBorderGetSize function.
Description
This function operates with ROI (see Regions of Interest in Intel IPP). This function finds edges in the ROI of the source image with the user-defined border types using the Canny edge detector algorithm. The output image is stored in
pDst
.
Before using this function, compute the size of the temporary work buffer using the CannyBorderGetSize function.
Return Values
ippStsNoErr
Indicates no error. Any other value indicates an error or a warning.
ippStsNullPtrErr
Indicates an error when one of the specified pointers is
NULL
.
ippStsMaskSizeErr
Indicates an error when
mask
has an illegal value.
ippStsSizeErr
Indicates an error when
roiSize
has a field with a zero or negative value.
ippStsStepErr
Indicates an error when
srcStep
or
dstStep
is less than
roi.width
*
<pixelSize>.
ippStsBadArgErr
Indicates an error when
lowThresh
is negative, or
highThresh
is less than
lowThresh
.
ippStsNotEvenStepErr
Indicates an error when one of the step values is not divisible by 2 for
16s
images, and by 4 for
32f
images.

Example

/******************************************************************************* * Copyright 2015-2020 Intel Corporation. * * This software and the related documents are Intel copyrighted materials, and * your use of them is governed by the express license under which they were * provided to you (License). Unless the License provides otherwise, you may not * use, modify, copy, publish, distribute, disclose or transmit this software or * the related documents without Intel's prior written permission. * * This software and the related documents are provided as is, with no express * or implied warranties, other than those that are expressly stated in the * License. *******************************************************************************/ // A simple example of edge detection algorithm implemented with Intel(R) Integrated Performance Primitives (Intel(R) IPP) functions: // ippiCannyBorderGetSize // ippiCannyBorder_8u_C1R #include <stdio.h> #include "ipp.h" #define WIDTH 128 /* image width */ #define HEIGHT 64 /* image height */ #define THRESH_LOW 50.f /* Low threshold for edges detection */ #define THRESH_HIGHT 150.f /* Upper threshold for edges detection */ #define BORDER_VAL 0 /* Next two defines are created to simplify code reading and understanding */ #define EXIT_MAIN exitLine: /* Label for Exit */ #define check_sts(st) if((st) != ippStsNoErr) goto exitLine; /* Go to Exit if Intel(R) IPP function returned status different from ippStsNoErr */ /* Results of ippMalloc() are not validated because Intel(R) IPP functions perform bad arguments check and will return an appropriate status */ int main(void) { IppStatus status = ippStsNoErr; Ipp8u* pSrc = NULL, *pDst = NULL; /* Pointers to source/destination images */ int srcStep = 0, dstStep = 0; /* Steps, in bytes, through the source/destination images */ IppiSize roiSize = { WIDTH, HEIGHT }; /* Size of source/destination ROI in pixels */ Ipp8u *pBuffer = NULL; /* Pointer to the work buffer */ int iTmpBufSize = 0; /* Common work buffer size */ IppiDifferentialKernel filterType = ippFilterScharr; pSrc = ippiMalloc_8u_C1(roiSize.width, roiSize.height, &srcStep); pDst = ippiMalloc_8u_C1(roiSize.width, roiSize.height, &dstStep); /* Start Edge Detection algorithm */ check_sts( status = ippiCannyBorderGetSize(roiSize, filterType, ippMskSize3x3, ipp8u, &iTmpBufSize) ) pBuffer = ippsMalloc_8u(iTmpBufSize); check_sts( status = ippiCannyBorder_8u_C1R(pSrc, srcStep, pDst, dstStep, roiSize, filterType, ippMskSize3x3, ippBorderRepl, BORDER_VAL, THRESH_LOW, THRESH_HIGHT, ippNormL2, pBuffer) ) EXIT_MAIN ippsFree(pBuffer); ippiFree(pSrc); ippiFree(pDst); printf("Exit status %d (%s)\n", (int)status, ippGetStatusString(status)); return (int)status; }

Product and Performance Information

1

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Notice revision #20110804