BGR565ToYCbCr420, BGR555ToYCbCr420

Converts a 16-bit per pixel BGR image to the YCbCr image that has 4:2:0 sampling format.

Syntax

IppStatus ippiBGR565ToYCbCr420_16u8u_C3P3R(const Ipp16u* pSrc, int srcStep, Ipp8u* pDst[3], int dstStep[3], IppiSize roiSize);

IppStatus ippiBGR555ToYCbCr420_16u8u_C3P3R(const Ipp16u* pSrc, int srcStep, Ipp8u* pDst[3], int dstStep[3], 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.
roiSize	Size of the source and destination ROI in pixels.

Description

The functions ippiBGR565ToYCbCr420 and ippiBGR555ToYCbCr420 are declared in the ippcc.h file. They operate with ROI (see Regions of Interest in Intel IPP).

These functions convert a three-channel gamma-corrected B'G'R' image pSrc to the planar Y'Cb'Cr' image pDst according to the same formulas as the function ippiRGBToYCbCr does. The destination image has the 4:2:0 sampling format (see Table “Planar Image Formats” for more details).

The source image pSrc is a packed 16-bit BGR image with reduced bit depth; all 3 channel intensities for a pixel are packed into two consecutive bytes (16u data type). It can be in one of two possible formats (see Figure 16-bit Pixel Formats for more details): BGR565 (5 bits for blue, 6 bits for green, 5 bits for red), and BGR555 (5 bits for blue, green, red).

roiSize.width and roiSize.height should be multiples of 2. If not 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.