What does Chroma in Profile Inspector measures?

CHROMiX ColorThink
1

Hi,

Is the quality of a profile related with its Chroma values shown in the Inspector measures? :confused:

Thanks,
Juan Dent

2

Hi Juan,

I’m not sure what you mean here. Where do you see “Chroma” in the Profile Inspector? If you could give a step by step account of what you are doing, or what you are trying to do, I could get a better idea of what you’re seeing.

3

Hi,

Yes, the scenario is the following: I open ProfileInspector on any printer profile I have created with EyeOneMatch 3 and go to the Curves tab.
As I move sideways, I find that the lower right radial diagram labled Chroma has the red dot moving around instead of remaining in the center - this is the Chroma values that I do not quite understand what they mean? Is the profile’s validity related to how fixed to the center the Chroma remains as I move sideways? Why do I find more motion in Relative Colorimetric mode compared to Absolute Colorimetric?

Is this clear?
:confused: Thanks

4

Ah… excellent question. As it turns out we did not get an explanation of Chroma window into the ColorWiki manual, so Thank-You for bringing this to our attention. I’ll put this answer into the ColorThink manual in a few days.

The Chroma window describes at what point (in Lab space) is the neutral axis of the profile, for any given L (lightness) value. It is as if you were looking down the center of the profile and seeing where the grays differ from the center of Lab. The numbers on top of the Chroma bullseye window are the “a” and “b” values. The Chroma value below the windows tells you how many Chroma values away from Lab neutral that point is. The concentric rings each represent one delta E.

So, to use the example in the ColorWiki, at an L value of 5.1, the a value would be -.3 and the b value would be 1.0. This is a slightly green point approximately 1 delta E away from neutral.

Therefore, this window is not necessarily an indication of how accurate your profile is, but is a good gauge of how much work your profile is doing to get your color into shape.

Here’s a link to this page in the manual.
http://www.colorwiki.com/wiki/ColorThink_Pro_-Profile_Inspector%26_Renamer#Curves_Tab