Explicit comparison to reference gamuts is limited at present. The outer ring of up to two references can be plotted, however this shows no detail of where on the lightness range a test gamut may differ from the reference.
There is a property RingReference, however this just provides two different ways of showing where a test gamut exceeds a reference gamut, to deal with the case where the test gamut is generally smaller than the reference gamut, but exceeds it in places (one place where the rings plot is not intuitive to some is that although a set of rings is entirely inside the displayed reference, this does not mean that it is uniformly so). This is set via the RingReference property:
‘none’ means do nothing (of course)
‘ref’ means plot a dotted line within a band showing where the ref gamut is less than the test.
‘intersection’ means plot a dotted line within a band showing where the intersection of the ref and test gamut is less than the test.
The point behind these was that they provided a little more info without modifying the overall rings plot. I would argue that ref can be useful, depending what insight somebody is after. Intersection is less so, I think, and the two are unlikely to produce very different answers either.
Proposal
I would like to add a property or option to plot the rings of the reference and show the intersection of the test gamut within that.
I would suggest four new properties:
ShowRefBands: true | false (default)
this will indicate to plot bands of the reference gamut. In practice the coloured bands will be the MAX of the test and ref gamuts – the test rings will be solid, the reference rings (if shown, defined by the RingReference property above) will be dashed.
select if the test gamut plotted should be first intersected with the reference.
So, by default, if ‘ShowRefBands’ is set to true then what will be plotted are rings indicating the ref gamut with the intersected area colourful and outside that grey, with the solid lines around the colourful (intersected test) bands.
This, I think, is consistent with the properties we have so far.
If we also want to enable plots such as those shown here, with the orange (or some other) block fill colour, then I suggest we add two more properties:
BandHue: 0 – 359 | ‘match’
the hue of the test bands where ‘follow’ indicates matching the plot angle, and where the hue angle is zero for a=1, b=0 and 90 for a=0, b=1.
RefBandHue
as BandHue but for the reference bands.
This fits with how things are defined at the moment (i.e. you can already control the Chroma and Lightness, now you can also set the Hue) and gives flexibility.
Finally given the shear number of options I also suggest (eventually?) adding the following:
defaults: 'CIELab-gamut-tools' | other names...
set multiple properties to produce a plot which conforms to particular standards.
Existing provision for gamut rings comparison
Explicit comparison to reference gamuts is limited at present. The outer ring of up to two references can be plotted, however this shows no detail of where on the lightness range a test gamut may differ from the reference.
There is a property RingReference, however this just provides two different ways of showing where a test gamut exceeds a reference gamut, to deal with the case where the test gamut is generally smaller than the reference gamut, but exceeds it in places (one place where the rings plot is not intuitive to some is that although a set of rings is entirely inside the displayed reference, this does not mean that it is uniformly so). This is set via the RingReference property:
Proposal
I would like to add a property or option to plot the rings of the reference and show the intersection of the test gamut within that.
I would suggest four new properties:
So, by default, if ‘ShowRefBands’ is set to true then what will be plotted are rings indicating the ref gamut with the intersected area colourful and outside that grey, with the solid lines around the colourful (intersected test) bands.
This, I think, is consistent with the properties we have so far.
If we also want to enable plots such as those shown here, with the orange (or some other) block fill colour, then I suggest we add two more properties:
This fits with how things are defined at the moment (i.e. you can already control the Chroma and Lightness, now you can also set the Hue) and gives flexibility.
Finally given the shear number of options I also suggest (eventually?) adding the following: