Filtering Functions

Intel® IPP implements image processing functions that perform linear and non-linear filtering operations on an image.

Filtering can be used in a variety of image processing operations; for example, edge detection, blurring, noise removal, and feature detection.

Table Filtering Functions lists the Intel IPP filtering functions described in more detail later in this chapter:

Filtering functions
Function Base Name	Operation
FilterBox	Blurs an image using a box filter.
SumWindowRow	Sums pixel values in the row mask applied to the image.
SumWindowColumn	Sums pixel values in the column mask applied to the image.
FilterMin	Filters an image using a min filter.
FilterMax	Filters an image using a max filter.
FilterMinGetBufferSize	Computes the size of the working buffer for the minimum filter.
FilterMaxGetBufferSize	Computes the size of the working buffer for the maximum filter.
FilterMinBorderReplicate	Filters an image using a min filter with border replication.
FilterMaxBorderReplicate	Filters an image using a max filter with border replication.
FilterBilateralGetBufSize	Computes the size of the buffer for the bilateral filter.
FilterBilateralInit	Initializes the bilateral filter structure.
FilterBilateral	Performs bilateral filtering of the image.
DecimateFilterRow, DecimateFilterColumn	Decimates an image using the specified filter.
Median Filters
FilterMedianGetBufferSize	Compute the size of the external buffer.
FilterMedian	Applies a median filter to an image.
FilterMedianHoriz	Filters an image using a median filter with a horizontal mask.
FilterMedianVert	Filters an image using a median filter with a vertical mask.
FilterMedianCross	Filters an image using a cross median filter.
FilterMedianWeightedCenter3x3	Filters an image using a median filter with weighted center pixel.
FilterMedianColor	Applies a color median filter to an image.
General Linear Filters
Filter	Filters an image using a general rectangular convolution kernel.
FilterGetBufSize	Compute the size of working buffer for 64f general linear filter.
Filter32f	Filters an image with integer data using a floating-point rectangular convolution kernel.
Filter_Round16s, Filter_Round32s, Filter_Round32f	Perform filtering an image and rounding the result.
FilterRoundGetBufSize16s, FilterRoundGetBufSize32s, FilterRoundGetBufSize32f	Computes the size of the working buffer for filters with rounding mode.
Separable Filters
FilterColumn	Filters an image using an integer column convolution kernel.
FilterColumn32f	Filters an image using a floating-point column convolution kernel.
FilterRow	Filters an image using an integer row convolution kernel.
FilterRow32f	Filters an image using a floating-point row convolution kernel.
FilterRowBorderPipelineGetBufferSize, FilterRowBorderPipelineGetBufferSize_Low	Compute the size of working buffer for rows filter with border.
FilterColumnPipelineGetBufferSize, FilterColumnPipelineGetBufferSize_Low	Compute the size of working buffer for columns filter with border.
FilterRowBorderPipeline, FilterRowBorderPipeline_Low	Applies the filter with border to image rows.
FilterColumnPipeline, FilterColumnPipeline_Low	Applies the filter with border to image columns.
DotProdCol	Calculates the dot product of taps vector and columns of the specified set of rows.
Wiener Filters
FilterWienerGetBufferSize	Computes the size of the external buffer for ippiFilterWiener function.
FilterWiener	Filters an image using the Wiener algorithm.
Convolution
ConvFull	Performs full convolution of two images.
ConvValid	Performs valid convolution of two images.
Deconvolution
DeconvFFTInitAlloc	Allocates and initializes state structure for FFT deconvolution.
DeconvFFTFree	Frees memory allocated for the FFT deconvolution state structure.
DeconvFFT	Performs FFT deconvolution of an image.
DeconvLRInitAlloc	Allocates and initializes state structure for LR deconvolution.
DeconvLRFree	Frees memory allocated for the LR deconvolution state structure.
DeconvLR	Performs LR deconvolution of an image.
Fixed Filters
FilterPrewittHoriz	Filters an image using a horizontal Prewitt operator.
FilterPrewittVert	Filters an image using a vertical Prewitt operator.
FilterScharrHoriz	Filters an image using a horizontal Scharr operator.
FilterScharrVert	Filters an image using a vertical Scharr operator.
FilterSobelHoriz, FilterSobelHorizMask	Filters an image using a horizontal Sobel operator.
FilterSobelVert, FilterSobelVertMask	Filters an image using a vertical Sobel operator.
FilterSobelHorizSecond	Filters an image using a second derivative horizontal Sobel operator.
FilterSobelVertSecond	Filters an image using a second derivative vertical Sobel operator.
FilterSobelCross	Filters an image using a second cross derivative Sobel operator.
FilterRobertsDown	Filters an image using a horizontal Roberts cross-gradient operator.
FilterRobertsUp	Filters an image using a vertical Roberts cross-gradient operator.
FilterLaplace	Filters an image using a Laplacian kernel.
FilterGauss	Filters an image using a Gaussian kernel.
FilterHipass	Applies a highpass filter to an image.
FilterLowpass	Applies a lowpass filter to an image.
FilterSharpen	Applies a sharpening filter to an image.
Fixed Filters with Borders
FilterScharrHorizGetBufferSize	Computes the size of the external buffer for the horizontal Scharr filter with border.
FilterScharrVertGetBufferSize	Computes the size of the external buffer for the vertical Scharr filter with border.
FilterSobelHorizGetBufferSize	Computes the size of the external buffer for the horizontal Sobel filter with border.
FilterSobelVertGetBufferSize, FilterSobelNegVertGetBufferSize	Computes the size of the external buffer for the vertical Sobel filter with border.
FilterSobelHorizSecondGetBufferSize	Computes the size of the external buffer for the second derivative horizontal Sobel filter with border.
FilterSobelVertSecondGetBufferSize	Computes the size of the external buffer for the second derivative vertical Sobel filter with border.
FilterSobelCrossGetBufferSize	Computes the size of the external buffer for the cross Sobel filter with border.
FilterLaplacianGetBufferSize	Computes the size of the external buffer for the Laplace filter with border.
FilterGaussGetBufferSize	Computes the size of the external buffer for the Gaussian filter with border.
FilterLowpassGetBufferSize	Computes the size of the external buffer for the lowpass filter with border.
GenSobelKernel	Computes kernel for the Sobel filter to an image.
FilterScharrHorizBorder	Applies horizontal Scharr filter with border to an image.
FilterScharrVertBorder	Applies vertical Scharr filter with border to an image.
FilterSobelHorizBorder	Applies horizontal Sobel filter with border to an image.
FilterSobelVertBorder, FilterSobelNegVertBorder	Applies vertical Sobel filter with border to an image.
FilterSobelHorizSecondBorder	Applies horizontal (second derivative) Sobel filter with border to an image.
FilterSobelVertSecondBorder	Applies vertical (second derivative) Sobel filter with border to an image.
FilterSobelCrossBorder	Applies second derivative cross Sobel filter with border to an image.
FilterLaplacianBorder	Applies Laplacian filter with border to an image.
FilterGaussBorder	Applies Gauss filter with border.
FilterLowpassBorder	Applies lowpass filter with border to an image.

Most of filtering function operate with ROI (see Regions of Interest in Intel IPP). The size of the source image ROI is equal to dstRoiSize, the destination image ROI size. Most of the functions use different source and destination image buffers, that is, they are not in-place.