Intel® Integrated Performance Primitives Developer Guide and Reference

ID 790148
Date 11/07/2023
Public

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Document Table of Contents

YCCToRGB

Converts a YCC image to the RGB color model.

Syntax

IppStatus ippiYCCToRGB_<mod>(const Ipp<datatype>* pSrc, int srcStep, Ipp<datatype>* pDst, int dstStep, IppiSize roiSize);

Supported values for mod:

8u_C3R 16u_C3R 16s_C3R 32f_C3R
8u_AC4R 16u_AC4R 16s_AC4R 32f_AC4R

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

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

This function operates with ROI (see Regions of Interest in Intel IPP).

This function converts the PhotoY'C'C' image pSrc to the R'B'G' image pDst. The function ippiYCCToRGB first restores normal luminance and chrominance data as:

Y' = 1.3584 * Y'

C1' = 2.2179 * (C1' - 156./255.)

C2' = 1.8215 * (C2' - 137./255.)

The equations above are given on the assumption that source Y, C1, and C2 values are normalized to the range [0..1]. In case of the floating-po int data type, the input YCC values must already be in the range [0..1]. For integer data types, normalization is done by the conversion function internally.

After that, YCC data are transformed into RGB format according to the following basic equations:

R' = Y' + C2'

G' = Y' - 0.194*C1' - 0.509*C2'

B' = Y' + C1'

In case of integer function flavors, the computed R'B'G' values are then scaled to the full range of the destination data type (see Table “Image Data Types and Ranges”).

Return Values

ippStsNoErr

Indicates no error. Any other value indicates an error.

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.