[Openicc] Gutenprint mission ... Printer profiling workflow

[Chris Murphy]

On May 16, 2012, at 2:14 AM, Kai-Uwe Behrmann wrote:

> Am 15.05.12, 13:42 -0600 schrieb Chris Murphy:
>> I vaguely recall a discussion, maybe a year ago, about this. PDF had an unambiguous way to describe a PDF whose contents should not be transformed. But the /device spaces have been hijacked by virtue of assumed and default source profiles. So it's arguably no longer ambiguous when "no transforms" is specified.
> 
> PDF/X-3 is the still worked on answere for this question.

Maybe. The OutputIntent set in the profile target PDF will not match pretty match any device or queue in the real world. So is your default behavior to simulate the OutputIntent, as is the case for displays (including Acrobat), or is the default behavior to output device values? I don't know if the spec says what the default is supposed to be for printing. I'd like to think, as a print specific format, we'd honor the file and say the OutputIntent is there as a check, and optionally to be used for repurposing (proofing or soft proofing). But is that how Ghostscript presently behaves? Is that how Mac OS X behaves?

I think Leonard opined on this some time ago.

> 
>> It's even possible a PDF reader will extract objects, causing a whole new PDF spool to be produced, rather than insert the existing PDF into the print stream. So I'm not sure it can be made reliable even for PDF (or XPS).
> 
> We have to assume to print from colour management aware applications in order to calibrate and profile. But that should not surprise. If extraction does not work for ICC tags, then that is a bug in the app, and either it is fixed or will not be recommendable.

The case does appear to be, either you need color management aware apps to opt in to color transforms. Or you need color management aware apps to opt out of color transforms. If the axiom is to be "the needs of the many outweighs the needs of the few" then we need apps that know how to disable ICC based transforms in the display and print pipeline.

Chris Murphy