[Openicc] printing GUI vs. printerdriver, LINUX colorinfrastructure

[Graeme Gill]

Hal V Engel wrote:

> For color critical work my personal experience indicates that profiles will 
> only give me the results I want with a very narrow range of mode/media 
> combinations.  In color critical work the biggest variable is the paper.  In 
> general if I custom profile the Ilford Galoria Gloss paper I use at say 
> 1440DPI that profile will still work well enough for color critical work at 
> 2880DPI and 720DPI with the same paper.  But not at 360DPI or lower.  And I 
> would not expect that same profile to work as well with say Epson Premium 
> Glossy paper.  But this likely would be close enough for less critical uses.

For really critical work, nothing will substitute for a custom profile.
Are you using a calibration system in your context though ?
A calibration system (typically automatic device linearisation) stretches
canned profiles further.


> Of course this assumes the existence of profiling tools that will create the 
> needed tags either at the time the profile is created or that will add the 
> tags later.  None of the tools that I use currently have this capability.  
> But it should not be hard to implement a tool that adds these tags to a 
> profile.  In the long run we will need to implement open source profilers for 
> printers as at present the only open source tools I know of are the command 
> line tools in Argyllcms and I don't know how close these are to being usable 
> in a production environment.

This is part and parcel of such a scheme (although I can
think of workarounds - naming the file or a directory to contain it
would also work, but is more fragile in the long run.) Having protocols
to link with the profiler would make it easier and more foolproof.
[In the ArgyllCMS context, a lump of CGATS style device setup information
  to be inserted in the .ti3 measurement file would be the natural way to
  go. ]

> It might even be possible to use these tags to help out the "fuzzy" profile 
> matching by including additional information beyond the specific printer mode 
> involved such as allowing the profile creator to indicate a range of settings 
> that should work "good enough" and perhaps also the specific paper that the 
> profile was intended for.  So the "fuzzy" algorithm would then know that this 
> profile is best if used at 1440DPI but will also give satisfactory results at 
> any resolution 720DPI and up for example.   The user would also be told that 
> this particular profile was intended for say Epson Premium Glossy paper to 
> help the user decide if this profile is good enough.  So it appears to me 
> that using the private ICC tags could be a very powerful tool to help users 
> get the best possible results from canned profiles.

It's a general lack in the ICC format. There was an attempt to accommodate this
type of thing with the icSigDeviceSettingsTag, but this seems to have been dropped
from the latest spec.
I was thinking that the fuzzy matching algorithm tuning might be device
information, but allowing for a range of "perfect match" wouldn't be
too hard to allow for.

Graeme Gill.