Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference
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RGBToYCbCr420
Converts an RGB image to the YCbCr color model; uses 4:2:0 sampling.
Syntax
IppStatus ippiRGBToYCbCr420_8u_C3P3R(const Ipp8u* pSrc, int srcStep, Ipp8u* pDst[3], int dstStep[3], IppiSize roiSize);
IppStatus ippiRGBToYCbCr420_8u_C3P2R(const Ipp8u* pSrc, int srcStep, Ipp8u* pDstY, int dstYStep, Ipp8u* pDstCbCr, int dstCbCrStep, IppiSize roiSize);
IppStatus ippiRGBToYCbCr420_8u_C4P2R(const Ipp8u* pSrc, int srcStep, Ipp8u* pDstY, int dstYStep, Ipp8u* pDstCbCr, int dstCbCrStep, IppiSize roiSize);
Include Files
ippcc.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 | An array of pointers to ROI in the separate planes of the destination image for three-plane image. | 
| dstStep | Array of distances in bytes between starts of consecutive lines in each plane of the destination image for three-plane image. | 
| pDstY | Pointer to ROI in the luminance plane of the destination image for two-plane image. | 
| dstStep, dstYStep | Distance in bytes between starts of consecutive lines in the luminance plane for two-plane image. | 
| pDstCbCr | Pointer to ROI in the interleaved chrominance plane of the destination image for two-plane image. | 
| dstCbCrStep | Distance in bytes between starts of consecutive lines in the interleaved chrominance plane for two-plane image. | 
| roiSize | Size of the source and destination ROI in pixels. | 
Description
This function operates with ROI (see Regions of Interest in Intel IPP).
This function converts the gamma-corrected R'G'B' image pSrc to the Y'Cb'Cr' image according to the same formulas as the function ippiRGBToYCbCr does. The difference is that ippiRGBToYCbCr420 uses 4:2:0 sampling format for the converted image (see Table “Planar Image Formats” for more details).
roiSize.width should be multiple of 2, and roiSize.height should be multiple of 2 (for three-plane image) or 4 (for two-plane image). If not the function reduces their original values to the nearest multiples of 2 or 4 correspondingly, performs operation, and returns 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 has a field with value less than 2. | 
| ippStsDoubleSize | Indicates a warning if roiSize.width is not a multiple of 2, or if roiSize.height is not a multiple of 2 (for three-plane image) or 4 (for two-plane image). |