xyz2srgb
The xyz2srgb function calculates the transformation of CIE 1931 x,y,z chromaticity coordinates to srgb for plotting in Matlab or Octave.
Usage:
srgb = xyz2srgb(xyz,'wp','method')
Where:
| Parameter | Description |
srgb | Is the resulting srgb triplet vector or matrix [r g b]. |
xyz | Is the CIE xyz input triplet vector or matrix [x y z]. |
'wp' | Specifies the reference whitepoint, see ciewhitepoint below or use a vector triplet [x y z]. Default: ‘D65’ |
'method' | Chromatic adaptation method: – ‘XYZ’ (default) – ‘vonKries’ – ‘Bradford’ |
Example:
Transformation of CIE 1931 x,y,z to srgb chromaticity and back:
xyz = [0.2905 0.3405 0.3261] srgb = xyz2srgb(xyz) xyz = srgb2xyz(srgb)
See also: srgb2xyz
Result:
xyz = 0.2905 0.3405 0.3261 srgb = 0.5424 0.6428 0.5761 xyz = 0.2905 0.3405 0.3261
Transformation of CIE 1931 x,y,z to srgb chromaticity and back using reference whitepoint ‘D65’:
xyz = [0.2905 0.3405 0.3261] srgb = xyz2srgb(xyz,'D50') xyz = srgb2xyz(srgb,'D50')
See also: srgb2xyz
Result:
xyz = 0.2905 0.3405 0.3261 srgb = 0.4729 0.6493 0.6664 xyz = 0.2905 0.3405 0.3261
Transformation of CIE 1931 x,y,z to srgb chromaticity and back using reference whitepoint ‘D50’ and ‘Bradford’ chromatic adaption method:
xyz = [0.2905 0.3405 0.3261] srgb = xyz2srgb(xyz,'D50','Bradford') xyz = srgb2xyz(srgb,'D50','Bradford')
See also: srgb2xyz
Result:
xyz = 0.2905 0.3405 0.3261 srgb = 0.4842 0.6492 0.6662 xyz = 0.2905 0.3405 0.3261
Plot CRI test colours:
lam = 380:780; spec = ciespec(lam,'CRI'); xyz = ciespec2xyz(lam,spec); srgb = xyz2srgb(xyz); plotcolour(srgb)
See also: ciespec, ciespec2xyz, plotcolours
Result:
Reference:
IEC 61966-2-1:1999, Multimedia systems and equipment - Colour measurement and management - Part 2-1: Colour management - Default RGB colour space - sRGB. Genf, Switzerland: International Electrotechnical Commission (IEC), 1999. URL: https://webstore.iec.ch/publication/6168
Chromatic adaptation: http://www.brucelindbloom.com/Eqn_ChromAdapt.html