FilterRobertsDownBorder
Filters an image using a horizontal Roberts edge filter.
Syntax
IppStatus ippiFilterRobertsDownBorder_<mod>(const Ipp<srcDatatype>*
pSrc
, int
srcStep
, Ipp<dstDatatype>*
pDst
, int
dstStep
, IppiSize
dstRoiSize
, IppiMaskSize
mask
, IppiBorderType
borderType
, Ipp<srcDatatype>
borderValue
, Ipp8u*
pBuffer
);
Supported values for
mod
:8u16s_C1R | 16s_C1R | 32f_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.
- pDst
- Pointer to the destination image ROI.
- dstStep
- Distance, in bytes, between the starting points of consecutive lines in the destination image.
- dstRoiSize
- Size of the source and destination ROI in pixels.
- mask
- Predefined mask ofIppiMaskSize. Possible value isippMskSize3x3.
- 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.
- ippBorderMirror
- Mirrored border is used.
- ippBorderMirrorR
- Mirrored border with replication is used.
- ippBorderInMem
- Border is obtained from the source image pixels in memory.
Mixed borders are also supported. They can be obtained by the bitwise operationORbetween any of theippBorderRepl,ippBorderConst,ippBorderMirror, orippBorderMirrorRvalues, and theippBorderInMemTop,ippBorderInMemBottom,ippBorderInMemLeft,ippBorderInMemRightvalues. - borderValue
- Constant value to assign to pixels of the constant border. This parameter is applicable only to theippBorderConstborder type.
- pBuffer
- Pointer to the work buffer.
Description
Before using this function, you need to compute the size of the work buffer
pBuffer
using the FilterRobertsDownBorderGetBufferSize
function. This function operates with ROI.
This function applies a horizontal Roberts edge filter to the
pSrc
source image ROI. The size of the source image ROI is equal to the destination image ROI size dstRoiSize
. The values of border pixels are assigned in accordance with the borderType
and borderValue
parameters. The kernel of the filter is a matrix of 3x3 size with the following values:0 0 0
0 1 0
0 0 -1
The anchor cell is the center cell of the kernel, highlighted in red.
This filter provides the gross approximation of the pixel values gradient in the horizontal direction.
Return Values
- ippStsNoErr
- Indicates no error.
- ippStsNullPtrErr
- Indicates an error when one of the specified pointers isNULL.
- ippStsSizeErr
- Indicates an error whendstRoiSizeis negative, or equal to zero.
- ippStsStepErr
- Indicates an error whensrcStepordstStepis negative, or equal to zero.
- ippStsNotEvenStepErr
- Indicates an error when one of the step values is not divisible by 4 for floating-point images, or by 2 for short-integer images.
- ippStsBorderErr
- Indicates an error whenborderTypehas an illegal value.
Example
/*******************************************************************************
* Copyright 2015-2021 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 performing linear filtering of an image using one of predefined convolution kernels
// implemented with Intel(R) Integrated Primitives (Intel(R) IPP) functions:
// ippiFilterPrewittHorizBorderGetBufferSize
// ippiFilterPrewittHorizBorder_8u16s_C1R
// ippiFilterPrewittVertBorderGetBufferSize
// ippiFilterPrewittVertBorder_8u16s_C1R
// ippiFilterRobertsDownBorderGetBufferSize
// ippiFilterRobertsDownBorder_8u16s_C1R
// ippiFilterRobertsUpBorderGetBufferSize
// ippiFilterRobertsUpBorder_8u16s_C1R
// ippiFilterScharrHorizMaskBorderGetBufferSize
// ippiFilterScharrHorizMaskBorder_8u16s_C1R
#include <stdio.h>
#include "ipp.h"
#define WIDTH 128 /* image width */
#define HEIGHT 128 /* image height */
/* 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; Ipp16s *pDst = NULL; /* Pointers to source/destination images */
int srcStep = 0, dstStep = 0; /* Steps, in bytes, through the source/destination images */
IppiSize srcImageSize = { WIDTH + 1, HEIGHT + 1 }; /* size of source image in pixels */
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 */
IppiMaskSize mask = ippMskSize3x3; /* Predefined mask of IppiMaskSize type. */
IppDataType srcDataType = ipp8u, dstDataType = ipp16s;
IppiBorderType borderType = (IppiBorderType)(ippBorderRepl | ippBorderInMemTop | ippBorderInMemRight);
Ipp8u borderValue = 254;
int numChannels = 1;
pSrc = ippiMalloc_8u_C1(srcImageSize.width, srcImageSize.height, &srcStep);
pDst = ippiMalloc_16s_C1(roiSize.width, roiSize.height, &dstStep);
/* Filters and image using a horizontal Prewitt filter */
check_sts( status = ippiFilterPrewittHorizBorderGetBufferSize(roiSize, mask, srcDataType, dstDataType, numChannels, &iTmpBufSize) )
pBuffer = ippsMalloc_8u(iTmpBufSize);
check_sts( status = ippiFilterPrewittHorizBorder_8u16s_C1R(pSrc + srcStep, srcStep, pDst, dstStep, roiSize, mask, borderType, borderValue, pBuffer) )
ippsFree(pBuffer);
pBuffer = NULL;
/* Filters and image using a vertical Prewitt filter */
check_sts( status = ippiFilterPrewittVertBorderGetBufferSize(roiSize, mask, srcDataType, dstDataType, numChannels, &iTmpBufSize) )
pBuffer = ippsMalloc_8u(iTmpBufSize);
check_sts( status = ippiFilterPrewittVertBorder_8u16s_C1R(pSrc + srcStep, srcStep, pDst, dstStep, roiSize, mask, borderType, borderValue, pBuffer) )
ippsFree(pBuffer);
pBuffer = NULL;
/* Filters an image using a horizontal Roberts kernel. */
check_sts( status = ippiFilterRobertsDownBorderGetBufferSize(roiSize, mask, srcDataType, dstDataType, numChannels, &iTmpBufSize) )
pBuffer = ippsMalloc_8u(iTmpBufSize);
check_sts( status = ippiFilterRobertsDownBorder_8u16s_C1R(pSrc + srcStep, srcStep, pDst, dstStep, roiSize, mask, borderType, borderValue, pBuffer) )
ippsFree(pBuffer);
pBuffer = NULL;
/* Filters an image using a vertical Roberts edge filter */
check_sts( status = ippiFilterRobertsUpBorderGetBufferSize(roiSize, mask, srcDataType, dstDataType, numChannels, &iTmpBufSize) )
pBuffer = ippsMalloc_8u(iTmpBufSize);
check_sts( status = ippiFilterRobertsUpBorder_8u16s_C1R(pSrc + srcStep, srcStep, pDst, dstStep, roiSize, mask, borderType, borderValue, pBuffer) )
ippsFree(pBuffer);
pBuffer = NULL;
/* Filters an image using a horizontal Scharr kernel */
check_sts( status = ippiFilterScharrHorizMaskBorderGetBufferSize(roiSize, mask, srcDataType, dstDataType, numChannels, &iTmpBufSize) )
pBuffer = ippsMalloc_8u(iTmpBufSize);
check_sts( status = ippiFilterScharrHorizMaskBorder_8u16s_C1R(pSrc + srcStep, srcStep, pDst, dstStep, roiSize, mask, borderType, borderValue, pBuffer) )
EXIT_MAIN
ippsFree(pBuffer);
ippiFree(pSrc);
ippiFree(pDst);
printf("Exit status %d (%s)\n", (int)status, ippGetStatusString(status));
return (int)status;
}