Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference
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FilterSobelVertBorder
Filters an image using a vertical Sobel filter.
Syntax
IppStatus ippiFilterSobelVertBorder_<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 | 
IppStatus ippiFilterSobelVertBorder_<mod>_T(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_T | 
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 of IppiMaskSize. Possible values are ippMskSize3x3 or ippMskSize5x5. | ||||||||||
| borderType | Type of border. Possible values are: 
 Mixed borders are also supported. They can be obtained by the bitwise operation OR between any of the ippBorderRepl, ippBorderConst, ippBorderMirror, or ippBorderMirrorR values and the ippBorderInMemTop, ippBorderInMemBottom, ippBorderInMemLeft, ippBorderInMemRight values. | ||||||||||
| borderValue | Constant value to assign to pixels of the constant border. This parameter is applicable only to the ippBorderConst border 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 FilterSobelVertBorderGetBufferSize function.
This function operates with ROI.
This function applies a vertical Sobel 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 or 5x5 size depending on the mask value. The kernels have the following values:
-1 -2 0 2 1
-1 0 1 -4 -8 0 8 4
-2 0 2 or -6 -12 0 12 6
-1 0 1 -4 -8 0 8 4
-1 -2 0 2 1
The anchor cell is the center cell of the kernel, highlighted in red.
This filter enhances vertical edges of an image.
Return Values
| ippStsNoErr | Indicates no error. | 
| ippStsNullPtrErr | Indicates an error when one of the specified pointers is NULL. | 
| ippStsSizeErr | Indicates an error when dstRoiSize is negative, or equal to zero. | 
| ippStsStepErr | Indicates an error when srcStep or dstStep is 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 when borderType has an illegal value. | 
Example
The code example below demonstrates how to use the ippiFilterSobelVertBorderGetBufferSize and ippiFilterSobelVertBorder functions.
IppStatus fix_sobel_8u16( void ) {
    Ipp8u pSrc[9*8] =
	    {
	        0, 1, 2, 120, 121, 122, 50, 51, 52,
	        1, 2, 3, 121, 122, 123, 52, 52, 53,
	        3, 4, 5, 130, 131, 132, 63, 64, 65,
	        4, 5, 6, 131, 132, 133, 64, 65, 66,
	        5, 6, 7, 132, 133, 134, 65, 66, 67,
         8, 7, 6, 134, 133, 132, 67, 66, 65,
         7, 6, 5, 133, 132, 131, 66, 65, 64,
         6, 5, 4, 132, 131, 130, 65, 64, 63
          };
    Ipp16s  pDst[8*7];
    Ipp8u   *pBuffer;
    IppiSize roiSize = {8, 7};
    IppiBorderType borderType = ippBorderRepl | ippBorderInMemTop | ippBorderInMemRight;
    int    srcStep = 9 * sizeof(Ipp8u);
    int    dstStep = 8 * sizeof(Ipp16s);
    int    bufferSize;
    IppStatus status;
    ippiFilterSobelVertBorderGetBufferSize(roiSize, ippMskSize3x3, ipp8u, ipp16s, 1, &bufferSize);
    pBuffer = ippsMalloc_8u(bufferSize);
    status = ippiFilterSobelVertBorder_8u16s_C1R(pSrc + srcStep, srcStep, pDst, dstStep, roiSize, ippMskSize3x3,
             borderType, 0, pBuffer);
    ippsFree(pBuffer);
    return status;
}
 
    
   The result is as follows:
pDst -> -4 -8 -483 -483 -8 279 281 -6 -4 -8 -497 -497 -8 274 275 -7 -4 -8 -504 -504 -8 272 272 -8 -2 -4 -505 -505 -4 270 270 -4 2 4 -507 -507 4 266 266 4 4 8 -508 -508 8 264 264 8 4 8 -508 -508 8 264 264 8