BGRToCbYCr422

Converts BGR image to 16-bit per pixel CbYCr image for ITU-R BT.709 HDTV signal.

Syntax

IppStatus ippiBGRToCbYCr422_709HDTV_8u_C3C2R(const Ipp8u* pSrc, int srcStep, Ipp8u* pDst, int dstStep, IppiSize roiSize);

IppStatus ippiBGRToCbYCr422_709HDTV_8u_AC4C2R(const Ipp8u* pSrc, int srcStep, Ipp8u* pDst, int dstStep, IppiSize roiSize);

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 ROI in pixels.

Description

The function ippiBGRToCbYCr422_709HDTV is declared in the ippcc.h file. It operates with ROI (see Regions of Interest in Intel IPP).

This function converts the three- or four-channel gamma-corrected B'G'R' image pSrc to the two-channel Cb'Y'Cr' image pDst for digital component video signals complied with the ITU-R BT.709 Recommendation [ITU709] for high-definition TV (HDTV). The source image pixel values are in the range [16..235]. The conversion is performed according to the following formulas [Jack01]:

Y' = 0.213*R' + 0.715*G' + 0.072*B'

Cb' = -0.117*R' - 0.394*G' + 0.511*B' + 128

Cr' = 0.511*R' - 0.464*G' - 0.047*B' + 128

The values of Y' of the destination image are in the range [16..235], the values of Cb', Cr' are in the range [16..240]. They should be saturated at the 1 and 254 levels.

The function ippiBGRToCbYCr422_709HDTV uses the 4:2:2 sampling format for the converted image. The alpha-channel information is lost.

A CbYCr image has the following sequence of bytes: Cb0Y0Cr0Y1, Cb1Y2Cr1Y3, ... .

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error or a warning.
ippStsNullPtrErr	Indicates an error condition if pSrc or pDst pointer is NULL.
ippStsSizeErr	Indicates an error condition if roiSize has a field with a zero or negative value.