Re: Profile compression
Re: Profile compression
- Subject: Re: Profile compression
- From: Chris Murphy <email@hidden>
- Date: Wed, 1 Mar 2006 10:24:52 -0700
Tom,
This is a good example of why the ICC needs to update the
specification to allow for a bodyless profile. Basically it would
contain just the header, and a couple of URLs pointing to the actual
profile data which could then be kept up to date. The implementation
of this by the operating system vendors would involve caching the
body of the profile so that it would first search locally and then if
not found there it would use the URLs in the profile header to locate
that data (and then cache it for future use).
This doesn't solve your problem now, but we really need the ICC to
get on the stick. This has been a big pain point for CMYK based
workflows (among a number of other unrelated things), and I predict
it will be a problem for the larger ICC v4 versions of editing space
profiles such as sRGB and Adobe RGB. The ICC has to figure this out
VERY soon, so that the operating system vendors can implement this in
a reasonable time frame. If they do it now, there is a good chance
this could be implemented in the next major version of the OS's, but
if they diddle around for another year or more on this issue, then it
will just be that much longer.
My suggestion is to go to the ICC web site, www.color.org, and "Ask
Phil" in the upper right hand corner. When can we get header+URL
profiles? What's the time frame? The squeaky wheel gets the oil so
I'd make a point of asking this every few months. Standard time
frames for the ICC are glacial.
I've found binary files to not be very compressible, and that
includes ICC profiles. One way vendors make them smaller is to build
them using a smaller table size, which then compromises their
accuracy. Some vendors assume people won't use them for softproofing,
only for B2A conversions, so they'll put in high quality 33x33x33
matrix tables for B2A but use much smaller A2B tables to save size,
compromising the soft proof quality.
I haven't tried it, but you might give bzip2 a crack at an ICC
profile and see if they come out any smaller than just zip compression.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
-------------------------------------------------------------
Co-author "Real World Color Management, 2nd Edition"
Published by PeachPit Press (ISBN 0-321-26722-2)
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden