Visible to Intel only — GUID: GUID-FB126F92-23FD-4964-8D7B-3C96348E48DF
Visible to Intel only — GUID: GUID-FB126F92-23FD-4964-8D7B-3C96348E48DF
RGBToHLS
Converts an RGB image to the HLS color model.
Syntax
IppStatus ippiRGBToHLS_<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 R'B'G' image pSrc to the HLS image pDst. For function flavors operating on the floating point data, source RGB values must be in the range [0..1].
The conversion algorithm from RGB to HLS can be represented in pseudocode as follows:
// Lightness: M1 = max(R,G,B); M2 = min(R,G,B); L = (M1+M2)/2 // Saturation: if M1 = M2 then // achromatics case S = 0 H = 0 else // chromatics case if L <= 0.5 then S = (M1-M2) / (M1+M2) else S = (M1-M2) / (2-M1-M2) // Hue: Cr = (M1-R) / (M1-M2) Cg = (M1-G) / (M1-M2) Cb = (M1-B) / (M1-M2) if R = M1 then H = Cb - Cg //change R=M2 to R=M1 if G = M1 then H = 2 + Cr - Cb //change G=M2 to G=M1 if B = M1 then H = 4 + Cg - Cr //change B=M2 to B=M1 H = 60*H if H < 0 then H = H + 360
For floating point function flavors, the computed H, L, S values are scaled to the range [0..1]. In case of integer function flavors, these values are scaled to the full range of the destination data type (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. |