FilterSobelVertSecondBorder

Applies vertical (second derivative) Sobel filter with border.

Syntax

IppStatus ippiFilterSobelVertSecondBorder_<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

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 starts of consecutive lines in the source image.

pDst

Pointer to the destination image ROI.

dstStep

Distance in bytes between starts of consecutive lines in the destination image.

dstRoiSize

Size of the destination image ROI.

mask

Type of the filter kernel.

borderType

Type of border (see Borders in Neighborhood Operations); following values are possible:

ippBorderConst	Values of all border pixels are set to constant.
ippBorderRepl	Replicated border is used.
ippBorderMirror	Mirrored border is used
ippBorderMirrorR	Mirrored border with replication is used

borderValue

The constant value to assign to the pixels in the constant border (not applicable for other border's type).

pBuffer

Pointer to the working buffer.

Description

This function operates with ROI (see Regions of Interest in Intel IPP). This function applies the second derivative vertical Sobel filter (x-derivative) to the source image pSrc and stores results to the destination image of the same size pDst. Source image can be used as the destination image if they both have the same data type. The values of border pixels are assigned in accordance with the borderType and borderValue parameters. The kernel of this filter is the matrix of either 3x3 or 5x5 size that is specified by the parameter mask. The kernels have the following values with the anchor in the center cell (red):

                              1   0  -2   0   1

   1  -2   1                  4   0  -8   0   4

   2  -4   2       or         6   0 -12   0   6

   1  -2   1                  4   0  -8   0   4

                              1   0  -2   0   1

The function requires the working buffer pBuffer which size should be computed by the function ippiFilterSobelVertSecondBorderGetBufferSize beforehand.

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error or a warning.
ippStsNullPtrErr	Indicates an error condition if one of the specified pointers is NULL.
ippStsSizeErr	Indicates an error condition if roiSize has a field with a zero or negative value.
ippStsStepErr	Indicates an error condition if srcStep or dstStep is less than roiSize.width * <pixelSize>
ippStsNotEvenStepErr	Indicates an error condition if one of the step values is not divisible by 4 for floating-point images, or by 2 for short-integer images.
ippStsBadArgErr	Indicates an error if borderType or divisor has a wrong value.
ippStsMaskErr	Indicates an error condition if mask has a wrong value.

Example

/*******************************************************************************
* Copyright 2015 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.
*******************************************************************************/

//Perform linear filtering of an image using one of
//  predefined convolution kernels.
//     ippiFilterSobelVertSecondBorderGetBufferSize
//     ippiFilterSobelVertSecondBorder_8u16s_C1R

#include <stdio.h>
#include "ipp.h"

/* 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® Integrated Primitives (Intel® IPP) function returned status different from ippStsNoErr */

/* Results of ippMalloc() are not validated because Intel® IPP functions perform bad arguments check and will return an appropriate status  */

int main(void)
{

    IppStatus status = ippStsNoErr;
    Ipp8u pSrc[8*8]={
                     4, 4, 4, 4, 4, 4, 4, 4,
                     4, 3, 3, 3, 3, 3, 3, 4,
                     4, 3, 2, 2, 2, 2, 3, 4,
                     4, 3, 2, 1, 1, 2, 3, 4,
                     4, 3, 2, 1, 1, 2, 3, 4,
                     4, 3, 2, 2, 2, 2, 3, 4,
                     4, 3, 3, 3, 3, 3, 3, 4,
                     4, 4, 4, 4, 4, 4, 4, 4
                   };
    Ipp16s pDst[8*8];
    IppiSize roiSize = { 8, 8 };
    Ipp8u borderValue = 3;
    int pBufferSize = 0;
    Ipp8u* pBuffer = NULL;

    check_sts( status = ippiFilterSobelVertSecondBorderGetBufferSize(roiSize, ippMskSize3x3,
       ipp8u, ipp16s, 1, &pBufferSize))

    pBuffer = ippiMalloc_8u_C1 ( 8, 8, &pBufferSize );

    check_sts( status = ippiFilterSobelVertSecondBorder_8u16s_C1R ( pSrc, 8, pDst, 8*sizeof(Ipp16s), roiSize,
                         ippMskSize3x3, ippBorderConst, borderValue, pBuffer ) )

EXIT_MAIN
    ippsFree(pBuffer);
    printf("Exit status %d (%s)\n", (int)status, ippGetStatusString(status));
    return status;
}
/*
    Result:

    4 4 4 4 4 4 4 4
    4 3 3 3 3 3 3 4
    4 3 2 2 2 2 3 4
    4 3 2 1 1 2 3 4
    4 3 2 1 1 2 3 4     pSrc
    4 3 2 2 2 2 3 4
    4 3 3 3 3 3 3 4
    4 4 4 4 4 4 4 4


    -4 1 0 0 0 0 1 -4
    -7 2 1 0 0 1 2 -7
    -8 1 2 1 1 2 1 -8
    -8 0 1 3 3 1 0 -8
    -8 0 1 3 3 1 0 -8   pDst
    -8 1 2 1 1 2 1 -8
    -7 2 1 0 0 1 2 -7
    -4 1 0 0 0 0 1 -4

*/