DecimateFilterRow, DecimateFilterColumn

Decimates an image by the rows or by the columns.

Syntax

IppStatus ippiDecimateFilterRow_8u_C1R(const Ipp8u* pSrc, int srcStep, IppiSize srcRoiSize, Ipp8u* pDst, int dstStep, IppiFraction fraction);

IppStatus ippiDecimateFilterColumn_8u_C1R(const Ipp8u* pSrc, int srcStep, IppiSize srcRoiSize, Ipp8u* pDst, int dstStep, IppiFraction fraction);

Parameters

pSrc	Pointer to the source image ROI.
srcStep	Distance in bytes between starts of consecutive lines in the source image.
srcRoiSize	Size of the source image ROI in pixels.
pDst	Pointer to the destination image.
dstStep	Distance in bytes between starts of consecutive lines in the destination image.
fraction	Specifies how the decimating is performed. Possible values:
	ippPolyphase_1_2,
	ippPolyphase_3_5,
	ippPolyphase_2_3,
	ippPolyphase_7_10,
	ippPolyphase_3_4.

Description

The functions ippiDecimateFilterRow and ippiDecimateFilterColumn are declared in the ippi.h file. They operate with ROI (see Regions of Interest in Intel IPP).

These functions perform decimating of the source image by the rows or by the columns respectively. The functions used the set of special internal polyphase filters. The parameter fraction specifies how the decimating is performed, for example, if the parameter is set to ippPolyphase_3_5, then each 5 pixels in the row (or column) of the source image give 3 pixels in the destination image, if the parameter is set to ippPolyphase_1_2, then each two pixels in the row (or column) of the source image give 1 pixel in the destination image, an so on.

To ensure valid operation, the application must correctly define additional border pixels (see Borders). For all fraction values the width of the border is four column/rows all around the source image ROI.

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 or equal to 0.
ippStsDecimateFractionErr	Indicates an error condition if fraction has an illegal value.