Intel® Integrated Performance Primitives Developer Guide and Reference

ID 790148
Date 11/07/2023
Public

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Document Table of Contents

YCbCr422ToGray

Converts an interlaced 4:2:2 YCbCr or YCrCb image to gray-scale extracting luminance (Y) component.

Syntax

IppStatus ippiYCbCr422ToGray_8u_C2C1R(const Ipp8u* pSrc, int srcStep, Ipp8u* pDst, int dstStep, 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 the starting points of consecutive lines in the source image.

pDst

Pointer to the destination image ROI.

dstStep

Distance, in bytes, between the starting points of consecutive lines in the destination 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 an interlaced Y'Cb'Cr' or Y'Cr'Cb' image pSrc with the 4:2:2 sampling (see Table “Pixel-Order Image Formats” and Table “Planar Image Formats” for more details) to the gray-scale image pDst extracting luminance (Y) component.

Y'Cb'Cr' image with 4:2:2 sampling is also known as YUY2 format, and Y'Cr'Cb' as YVYU.

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 a zero or negative value.

Example

The code example below demonstrates how to use the ippiYCbCr422ToGray_8u_C2C1R function.

    const int WIDTH  = 2;
    const int HEIGHT = 2;

    Ipp8u pSrc[WIDTH * HEIGHT * 2] = {
        190,70,191,80,
        200,71,201,81,
    };
    Ipp8u pDst[WIDTH * HEIGHT];
    int srcStep = WIDTH * 2, dstStep  = WIDTH;
    IppiSize roiSize = {WIDTH, HEIGHT};
    IppStatus status = ippiYCbCr422ToGray_8u_C2C1R(pSrc, srcStep, pDst, dstStep, roiSize);
    if ( status == ippStsNoErr) 
        printf("PASS:\n%3d %3d\n%3d %3d\n", pDst[0], pDst[1], pDst[2], pDst[3]);
    else 
        printf("FAIL: status = %d\n", status);

Result:

PASS:
190 191
200 201