On Jan 29, 2013, at 11:10 AM, Benjamin De Kosnik <b...@redhat.com> wrote:
> 
> This is just scratching the surface. How are you going to evaluate
> quality? I'm concerned about the rasterization changes, the filter
> changes. Hopefully 1.6 may solve some of the image-quality regressions
> I've been seeing. 

Quality evaluation needs test targets/documents, and eyeballs. Many test 
targets are free or easily produced and could be CC0 licensed or something 
reasonable. This is something I've briefly discussed with Richard Hughes, and 
also participants in OpenICC, that are needed not just for print, but also for 
display. Perhaps some OpenICC and OpenPrinting collaboration is appropriate for 
acquiring test metrics.

Since CUPS itself doesn't rasterize, I don't expect you'd see changes in this 
area; but if there are filter changes, or an application decides to produce PDF 
job instead of PostScript, then it's possible, but probably not intended. If 
there are features or effects that need to be performed on a job after the 
application has produced the job, there are advantages to doing this on PDF 
than PostScript. But my expectation is even applications that today still use 
PostScript, they would be subject to the pstopdf filter, which in turn defers 
to Ghostscript on linux (Quartz2D by default on OS X) to turn it into a PDF. 
Such normalization of postscript to pdf is something that's been going on for 
many years, and is well tested (with many bug carcasses  along the way).

> 
> 4) In the past, I've found it difficult to debug cups filters step by
> step. Especially with so many rasterization/filter changes.

Yes this is tedious. Figuring out the sequence for a job isn't so difficult. 
But in case of problems, it would be useful to break the sequence, i.e. get 
access to the print job in a particular state in between filters. I've got some 
material on how to do this, for the purposes of troubleshooting the OS X print 
pipeline which of course uses CUPS, but different print drivers, raster engine, 
and color management philosophy.


> be updated? I would love it if issues like "what driver am I using"
> could be re-integrated into the UI, or perhaps an admin level of the
> ui. Also, "what filters did I run to get to this point of output" in a
> log file.

This is useful. At least on OS X each PDF print job also has a job ticket. I 
think this is a CUPS thing. Even once the job is complete, and the original 
document and raster files are deleted, the job ticket remains and it should 
contain all of this information. Making it more readable somehow might be 
useful.

> 
> 5) integration with common printing dialog. (IMHO localhost:631). 
> I think integrating Fedora's print dialogs with the wider user
> communities on macos and ubuntu would be very useful.

I'm not sure what common printing dialog refers to here. If it's the CPD, 
that's dead as far as I know, unless it's been raised in the last 2 months.

As for using Mac OS as a model for print dialogs, I'm happy to discuss exactly 
what areas I think this is useful and areas it's to be avoided. OS X for 
professional printing is nothing short of a clusterf|ck. It has been a huge 
PITA for me for ~8 years. Central to this problem is color, but also rather 
significantly is the UI/UX. We get *two* print dialogs for every print job with 
such applications due to lack of integration between the OS dialog and the 
application dialog. So we get an application dialog, and then later get an OS 
dialog, and they each contain mutually exclusive features, or settings that 
conflict between application and the OS. And the arbitration and assumption for 
this is not great, and not well documented. And this is aside from the separate 
interactions that occur with the print driver which does integrate with the OS 
dialog, but can itself have settings that conflict with the OS, or the 
application.

The UI/UX part isn't much different on Windows, but the color management 
ideology is, and that actually helps rather significantly for those who 
actually care about such things. So the hopeful idea is to mimic the successes 
of these companies, and avoid the mistakes. Should be easy. Ha!

Chris Murphy
-- 
devel mailing list
devel@lists.fedoraproject.org
https://admin.fedoraproject.org/mailman/listinfo/devel

Reply via email to