Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference

ID 790148
Date 3/22/2024
Public
Document Table of Contents

FilterLowpassBorder

Applies lowpass filter with border.

Syntax

IppStatus ippiFilterLowpassBorder_8u_C1R(const Ipp8u* pSrc, int srcStep, Ipp8u* pDst, int dstStep, IppiSize roiSize, IppiMaskSize mask, IppiBorderType borderType, Ipp8u borderValue, Ipp8u* pBuffer);

IppStatus ippiFilterLowpassBorder_32f_C1R(const Ipp32f* pSrc, int srcStep, Ipp32f* pDst, int dstStep, IppiSize roiSize, IppiMaskSize mask, IppiBorderType borderType, Ipp32f borderValue, Ipp8u* pBuffer);

Include Files

ippcv.h

Domain Dependencies

Headers: ippcore.h, ippvm.h, ipps.h, ippi.h

Libraries: ippcore.lib, ippvm.lib, ipps.lib, ippi.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.

roiSize

Size of the source and destination image ROI.

mask

Type of the filter kernel.

borderType

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

ippBorderConst

Values of all border pixels are set to constant.

ippBorderRepl

Replicated border 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 lowpass filter (blur operation) 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 anchor cell is the center cell (red) of the kernel.

The 3x3 filter uses the kernel with the following values:

          1/9  1/9  1/9
          1/9  1/9  1/9
          1/9  1/9  1/9

The 5x5 filter uses the kernel with the following values:

     1/25  1/25  1/25  1/25  1/25
     1/25  1/25  1/25  1/25  1/25
     1/25  1/25  1/25  1/25  1/25
     1/25  1/25  1/25  1/25  1/25
     1/25  1/25  1/25  1/25  1/25

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

ippStsBorderErr

Indicates an error condition if borderType has a wrong value.

ippStsMaskErr

Indicates an error condition if mask has a wrong value.