BGRToYCrCb420

Converts a BGR image to the YCrCb image with 4:2:0 sampling for ITU-R BT.709 CSC signal.

Syntax

IppStatus ippiBGRToYCrCb420_709CSC_8u_AC4P3R(const Ipp8u* pSrc, int srcStep, Ipp8u* pDst[3], int dstStep[3], IppiSize roiSize);

IppStatus ippiBGRToYCrCb420_709CSC_8u_C3P3R(const Ipp8u* pSrc, int srcStep, Ipp8u* pDst[3], int dstStep[3], IppiSize roiSize);

IppStatus ippiBGRToYCrCb420_709CSC_8u_C3P2R(const Ipp8u* pSrc, int srcStep, Ipp8u* pDstY, int dstYStep, Ipp8u* pDstCbCr, int dstCbCrStep, IppiSize roiSize);

Parameters

pSrc	Pointer to the source image ROI.
srcStep	Distance in bytes between starts of consecutive lines in the source image.
pDst	An array of pointers to ROI in separate planes of the destination image.
dstStep	An array of distances in bytes between starts of consecutive lines in the destination image planes.
pDstY	Pointer to the ROI in the luminance plane for a two-plane destination image.
dstYStep	Distance in bytes between starts of consecutive lines in the luminance plane of a destination image.
pDstCbCr	Pointer to the ROI in the interleaved chrominance plane for a two-plane destination image.
dstCbCrStep	Distance in bytes between starts of consecutive lines in the chrominance plane of a destination image.
roiSize	Size of the source and destination ROI in pixels.

Description

The function ippiBGRToYCrCb420_709CSC is declared in the ippcc.h file. It operates with ROI (see Regions of Interest in Intel IPP).

This function converts a three- or four-channel gamma-corrected B'G'R' image pSrc to the planar Y'Cr'Cb' image pDst for digital component video signals complied with the ITU-R BT.709 Recommendation [ITU709] for computer systems consideration (CSC). The source image pixel values are in the range [0..255]. The conversion is performed according to the following formulas [Jack01]:

Y' = 0.183*R' + 0.614*G' + 0.062*B' + 16

Cb' = -0.101*R' - 0.338*G' + 0.439*B' + 128

Cr' = 0.439*R' - 0.399*G' - 0.040*B' + 128

The destination image pDst has 4:2:0 sampling format (see Table “Planar Image Formats” for more details).

The values of roiSize.width and roiSize.height should be multiples of 2. Otherwise, the function reduces their original values to the nearest multiples of 2, performs the operation, and returns a warning message.

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error or a warning.
ippStsNullPtrErr	Indicates an error condition if pSrc or pDst is NULL.
ippStsSizeErr	Indicates an error condition if roiSize.width is less than 2 or roiSize.height is less than 2.
ippStsDoubleSize	Indicates a warning if roiSize has a field that is not a multiple of 2.