CHROMiX

Gamut Volume

Hello guys, it is my first topic here.

If it is possible, I’d like to know more about an information called Gamut Volume. What exactly is behind this? Is there any relation if I create a test chart with the same inks in the same conditions but with different numbers of patches?

If I compare two icc and I have different Gamut Volumes may I consider the bigger number as a bigger gamut?

Thanks in advance.

M

If you’re referring to the Gamut Volume calculation in the Profile Inspector, you can get more information on that in the ColorWiki:
colorwiki.com/wiki/ColorThin … r_Profiles

The “units” represented by the gamut volume are cubic Lab values.

You would not be able to acheive more volume, or a larger gamut, merely by adding more patches to a profiling chart. That would be something like adding more lines on a ruler - it won’t make the ruler any longer.

Between two gamuts, the one with the larger gamut volume is by definition a larger gamut. However the larger gamut may or may not be encompassing the smaller gamut. That’s why you have the Grapher in ColorThink! You can see exactly where the two gamuts differ, and if one “pokes out” in some areas where the other doesn’t.

Keep asking your questions. I love to answer ColorThink questions!

In the Relative Colorimetric Tag of CMYK profile, in principle, there are two gamuts which can be computed: the A2B1 gamut (easy to compute) and the B2A1 gamut (more challenging to compute). Which gamut do you display; or can you compute either one?

Harold Boll

ColorThink Pro can display either gamut. The gamut shape you see in the Grapher is the A2B direction, also known as the proofing direction of the profile. Viewing a profile this way will tell you the maximum possible gamut of your device, all the color it is capable of. The gamut volume number that is calculated in the Profile Inspector is based on this A2B 3 dimensional gamut. By default we present the Absolute Colorimetric gamut, but you can very easily change it to show you the Rel. Col. or any of the other rendering intents. More information on the theory behind ColorThink graphing is here:
colorwiki.com/wiki/Color_Man … yths_26-28

We also can display the B2A gamut, also known as the rendering, or printing direction of the profile - in the form of sampled points in the Grapher. A complete procedure for how you can do this is in this YouTube video:
youtube.com/watch?v=sTxaHhMYSYE

With ColorThink 2, you’ll be looking at the A2B gamut in the Grapher using the Abs. Col. rendering intent.