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

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 ippiYCCToRGB is declared in the ippcc.h file. It 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.