FilterSobelHorizBorder

Applies horizontal Sobel filter with border.

Syntax

IppStatus ippiFilterSobelHorizBorder_8u8s_C1R(const Ipp8u* pSrc, int srcStep, Ipp8s* pDst, int dstStep, IppiSize roiSize, IppiMaskSize mask, IppiBorderType borderType, Ipp8u borderValue, int divisor, Ipp8u* pBuffer);

IppStatus ippiFilterSobelHorizBorder_8u16s_C1R(const Ipp8u* pSrc, int srcStep, Ipp16s* pDst, int dstStep, IppiSize roiSize, IppiMaskSize mask, IppiBorderType borderType, Ipp8u borderValue, Ipp8u* pBuffer);

IppStatus ippiFilterSobelHorizBorder_32f_C1R(const Ipp32f* pSrc, int srcStep, Ipp32f* pDst, int dstStep, IppiSize roiSize, IppiMaskSize mask, IppiBorderType borderType, Ipp32f borderValue, Ipp8u* pBuffer);

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.

roiSize

Size of the source and destination image ROI.

mask

Type of the filter kernel.

borderType

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

ippBorderConst	Values of all border pixels are set to constant.
ippBorderRepl	Replicated border is used.
ippBorderWrap	Wrapped 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).

divisor

The constant value that output pixel value is divided by.

pBuffer

Pointer to the working buffer.

Description

The function ippiFilterSobelHorizBorder is declared in the ippcv.h file. It operates with ROI (see Regions of Interest in Intel IPP). This function applies the horizontal Sobel filter (y-derivative) to the source image pSrc and stores results to the destination image of the same size pDst. For the function flavor ippiFilterSobelHorizBorder_32f_C1R the source image can be used as the destination image. 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 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 -4
-1 -4 -6 -4 -1

The function requires the working buffer pBuffer whose size should be computed by the function ippiFilterSobelHorizGetBufferSize beforehand.

Example “Edge detection using the ippiCanny function” shows how the function ippiFilterSobelHorizBorder_8u16s_C1R can be used for edge detection.

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.