[Openicc] Linux CM ideology, was: meta data in test chart

[Chris Murphy]

On Feb 2, 2011, at 2:36 AM, Kai-Uwe Behrmann wrote:

> Am 01.02.11, 21:51 -0700 schrieb Chris Murphy:
>> What I really meant to say is that I don't know what their interest is in supporting a new direction, e.g. a derivative ICC specification, or whatever it would be. Whatever new direction would seem to require their involvement. And if they are involved in it, but not involved in Linux, I think open source still needs a say in the direction. I don't think getting a collection of companies who ultimately compete against each other is exactly the best collection of people to create a committee because it's a conflict of interest. We've already had that.
> 
> What could be the corner stones of a new or derived CMS?
> 
> * measurement based colour conversions

Well ICC.2, which may produce a v5 spec, is exactly about measurement based profiles and transformations being in the CMM. I do not know how clear the line is drawn, or where the line is drawn. But such effort requires substantially updated CMMs to support a major version change. And a big shift in responsibilities of where things go: right now we choose all sorts of profile building options in profile building software to define that transform at the time the profile is built; but in a new paradigm with transforms in CMMs, how do we communicate options to the CMM?

And in the case of Apple, they prevent any CMM except the Apple CMM from being used in the print pipeline. So if I'm using a hypothetical Argyll CMM and really like the results I'm getting on-screen and want to print, well I'm screwed unless I have a 100% reliable means to have Argyll prematch the data for print, and then submit the job to be untouched by the Apple CMM.

And this would be necessary in the CUPS, pdftoraster through GhostScript through lcms pipeline too. I'm pretty sure GhostScript 9 makes it possible (maybe even easy) to insert other CMMs into the pipeline. But this is a big shift to create software that works right in the guts of display and print pipelines, rather than as separate applications that build profiles and then step out of the way and aren't directly involved in the course of actual transforms.

Anyway, ICC v4 has taken a very long time to produce results and we're still not there yet. A very tiny percentage of workflows are v4, and IMO that is mostly incidental not by design. So any new or derived CMS has a very tall hill to climb to be adopted.


Chris Murphy