RGBToYCC

RGB to PhotoYCC color conversion. More...

Functions
NppStatus	nppiRGBToYCC_8u_C3R (const Npp8u *pSrc, int nSrcStep, Npp8u *pDst, int nDstStep, NppiSize oSizeROI)
	3 channel 8-bit unsigned packed RGB to 3 channel 8-bit unsigned packed YCC color conversion. More...
NppStatus	nppiRGBToYCC_8u_AC4R (const Npp8u *pSrc, int nSrcStep, Npp8u *pDst, int nDstStep, NppiSize oSizeROI)
	4 channel 8-bit unsigned packed RGB with alpha to 4 channel 8-bit unsigned packed YCC with alpha color conversion. More...

Detailed Description

RGB to PhotoYCC color conversion.

This is how NPP converts gamma corrected BGR or RGB to PhotoYCC. The computed Y, C1, C2 values are then quantized and converted to fit in the range [0..1] before expanding to 8 bits.

*  Npp32f nNormalizedR = (Npp32f)R * 0.003921569F; // / 255.0F

*  Npp32f nNormalizedG = (Npp32f)G * 0.003921569F;
*  Npp32f nNormalizedB = (Npp32f)B * 0.003921569F;
*  Npp32f nY = 0.299F * nNormalizedR + 0.587F  * nNormalizedG + 0.114F * nNormalizedB; 
*  Npp32f nC1 = nNormalizedB - nY;
*  nC1 = 111.4F * 0.003921569F * nC1 + 156.0F * 0.003921569F;
*  Npp32f nC2 = nNormalizedR - nY;
*  nC2 = 135.64F * 0.003921569F * nC2 + 137.0F * 0.003921569F;
*  nY = 1.0F * 0.713267F * nY; // / 1.402F

*  Y = (Npp8u)(nY  * 255.0F);
*  C1 = (Npp8u)(nC1 * 255.0F);
*  C2 = (Npp8u)(nC2 * 255.0F);
*  

Function Documentation

NppStatus nppiRGBToYCC_8u_AC4R	(	const Npp8u *	pSrc,
		int	nSrcStep,
		Npp8u *	pDst,
		int	nDstStep,
		NppiSize	oSizeROI
	)

4 channel 8-bit unsigned packed RGB with alpha to 4 channel 8-bit unsigned packed YCC with alpha color conversion.

Parameters

pSrc	Source-Image Pointer.
nSrcStep	Source-Image Line Step.
pDst	Destination-Image Pointer.
nDstStep	Destination-Image Line Step.
oSizeROI	Region-of-Interest (ROI).

Returns

Image Data Related Error Codes, ROI Related Error Codes

NppStatus nppiRGBToYCC_8u_C3R	(	const Npp8u *	pSrc,
		int	nSrcStep,
		Npp8u *	pDst,
		int	nDstStep,
		NppiSize	oSizeROI
	)

3 channel 8-bit unsigned packed RGB to 3 channel 8-bit unsigned packed YCC color conversion.

Parameters

pSrc	Source-Image Pointer.
nSrcStep	Source-Image Line Step.
pDst	Destination-Image Pointer.
nDstStep	Destination-Image Line Step.
oSizeROI	Region-of-Interest (ROI).

Returns

Image Data Related Error Codes, ROI Related Error Codes