Developer Reference

  • 2020
  • 07/15/2020
  • Public Content
Contents

HLSToRGB

Converts an HLS image to the RGB color model.

Syntax

IppStatus ippiHLSToRGB_<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
HLS
image
pSrc
to the
R'B'G'
image
pDst
. For function flavors operating on the floating point data, source HLS values must be in the range [0..1]. The conversion algorithm from
HLS
to
RGB
can be represented in pseudocode as follows:
if L <= 0.5 then M2 = L *(1 + S) else M2 = L + S - L * S M1 = 2 * L - M2 if S = 0 then R = G = B = L else h = H + 120 if h > 360 then h = h - 360 if h < 60 then R = ( M1 + ( M2 - M1 ) * h / 60) else if h < 180 then R = M2 else if h < 240 then R = M1 + ( M2 - M1 ) * ( 240 - h ) / 60 else R = M1 h = H if h < 60 then G = ( M1 + ( M2 - M1 ) * h / 60 else if h < 180 then G = M2 else if h < 240 then G = M1 + ( M2 - M1 ) * ( 240 - h ) / 60 else G = M1 h = H - 120 if h < 0 then h += 360 if h < 60 then B = ( M1 + ( M2 - M1 ) * h / 60 else if h < 180 then B = M2 else if h < 240 then B = M1 + ( M2 - M1 ) * ( 240 - h ) / 60 else B = M1
For floating point function flavors, the computed
R',G',B'
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 (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.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804