[Printing-architecture] [Gimp-print-devel] Looking ahead to 5.3
Alastair M. Robinson
blackfive at fakenhamweb.co.uk
Thu Oct 30 18:53:22 PDT 2008
Robert Krawitz wrote:
> I've been reading all this, but not responding; partly I've been busy
> and partly I'm curious what other folks think.
Ditto - I've been following the posts but not taking part for the last
few days, though I have fleshed out the Wiki a little since my last mail
on the subject.
> I'm still not a fan of requiring administrative privileges to use
> particular driver options of this kind that don't affect persistent
> state within the printer (and hence might have security implications).
Security implications are something I've been thinking about, actually.
In theory, it's possible for a printer to be damaged by feeding it
pathological input. Colour laser printers respond badly, I believe, to
being asked to print a solid page of 100% C+M+Y+K. Malicious
linearization curves could potentially result in flooding an inkjet,
too, I'd imagine.
> If something doesn't affect the system configuration or integrity it
> shouldn't require administrative privilege.
Agreed. Our difficulty is allowing users to set these options in a way
that makes them accessible to the driver running on the server but
doesn't affect other users' jobs.
(Note that the current CUPS configuration as shipped by Ubuntu - at
least in 8.04 - fails on this point. Any user with lp privileges can
set printer options which affect all other users.)
Oh, one other thing I've been wondering - are there currently, or are
there likely to be in future, any printer models which support
head-alignment, but don't have built-in persistent storage for that
> But I suppose I'm on the
> extreme end of maximum configurability and exposing (appropriately --
> which I might define differently from others) every possible option to
> the user, even if it allows someone to do absolutely absurd things.
"UNIX was not designed to stop its users from doing stupid things, as
that would also stop them from doing clever things." -- Doug Gwyn
> But there is a free RIP around Gutenprint (PhotoPrint) that could be
> extended to allow people to do this,
True - when I eventually get round to supporting curves!
> So the question is, how do we move along to that point?
Earlier today I began "thinking aloud" on that subject on the Wiki, and
took the first steps to adding "DeviceN" support to PhotoPrint's imaging
stack, in preparation for printing out raw per-channel linearization
Could you outline roughly how you currently go about tuning a new,
unknown printer, step-by-step? Understanding the steps and the order in
which they occur may be helpful in figuring out where the colour
instrument can help with the process, and how best to go about making
the results shareable.
All the best,
Alastair M. Robinson
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