[Openicc] XICC specification draft

[Ross Burton]

On Fri, 2005-06-24 at 02:22 +0800, Craig Ringer wrote:
> I'd suggest saying that the atom doesn't have to exist, and if it does
> not the display should be assumed to be uncalibrated. If no display
> profile is explicitly configured, the atom should be unset.
> 
> Stating the obvious, but you never know ... someone writing some config
> tool might well say "or, if I don't know what profile to use, I'll just
> set SRGB".

Good catch, thanks. I'd forgotten to document that case (despite that
being what my EoG patch does).

> http://bugs.scribus.net/view.php?id=2117

Excellent.

> One minor issue: "As profiles can be large applications should read the
> profile once, and cache it." Might that not become a significant memory
> cost if ICC support is integrated into toolkits etc, so every tiny
> application ends up reading and caching the profile? On the flipside
> there's bandwidth and context switches, so I don't know the right
> answer, but I thought I'd bring that up as a possible issue.

Yes, this could be an issue.  At one point I was tempted with adding
_ICC_PROFILE_FILE, which is a filename to the profile on disk (with the
requirements that _ICC_PROFILE must be set of _ICC_PROFILE_FILE is).
This would save traffic if the profile was large, but wouldn't save any
memory as (lcms at least) creates a new data structure from the profile
data, allowing the transfered data to be deleted.

Unless of course there is a way of working with profiles directly from
their on-disk format, in which case applications could mmap() the file
into memory if it exists.

I think I'll leave this for 0.2...

Thanks,
Ross
-- 
Ross Burton                                 mail: ross at burtonini.com
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