FilterSobelHorizBorder
Filters an image using a horizontal Sobel filter.
Syntax
IppStatus ippiFilterSobelHorizBorder_<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 ippiFilterSobelHorizBorder_<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 ofIppiMaskSize. Possible values areippMskSize3x3orippMskSize5x5.
- 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 FilterSobelHorizBorderGetBufferSize
function. This function operates with ROI.
This function applies a horizontal 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 4 6 4 1
1 2 1 2 8 12 8 2
0 0 0 or 0 0 0 0 0
-1 -2 -1 -2 -8 -12 -8 -2
-1 -4 -6 -4 -1
The anchor cell is the center cell of the kernel, highlighted in red.
This filter enhances horizontal edges of an image.
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
The code example below demonstrates how to use the
ippiFilterSobelHorizBorderGetBufferSize
and ippiFilterSobelHorizBorder_8u16s_C1R
functions to filter an image with the Sobel horizontal kernel.IppStatus fix_sobelhoriz_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; ippiFilterSobelHorizBorderGetBufferSize(roiSize, ippMskSize3x3, ipp8u, ipp16s, 1, &bufferSize); pBuffer = ippsMalloc_8u(bufferSize); status = ippiFilterSobelHorizBorder_8u16s_C1R(pSrc + srcStep, srcStep, pDst, dstStep, roiSize, ippMskSize3x3, borderType, 0, pBuffer); ippsFree(pBuffer); return status; }
The result is as follows:
pDst --> 12 12 19 33 40 43 49 52 12 12 19 33 40 42 47 51 8 8 8 8 8 8 8 8 14 8 5 7 4 2 6 4 6 0 -3 -1 -4 -6 -2 -4 -8 -8 -8 -8 -8 -8 -8 -8 -4 -4 -4 -4 -4 -4 -4 -4