[Openicc] colord 0.1.0 released!

[Chris Murphy]

On Jan 19, 2011, at 8:16 PM, Leonard Rosenthol wrote:

> On Wed, Jan 19, 2011 at 9:29 PM, Chris Murphy <lists at colorremedies.com> wrote:
>> There is NO DeviceRGB allowed in a PDF/X-3/4/5 file - all RGB data MUST be associated with an ICC profile.  You can have DeviceCMYK and DeviceGray - though they are actually only device values for the embedded OutputIntent.   The only "true" device-dependent colors in a PDF/X file are Spot/Separation colors, since they are resolved independently on each device.
> 
> OK at the expense of embarrassing myself, I'm going to ask it anyway: are you sure?
> 
> 
> From PDF/X-3 (ISO 15930-3, 6.2.2):
> The profile that is the value of the DestOutputProfile key, if present, shall be an Output Device Profile (Device Class = ‘prtr’) as defined in ICC.1.
> 
> From PDF/X-4 (ISo 15930-7:2010, 6.4.2.1):
> The profile that is the value of the DestOutputProfile key shall be an Output Device Profile (Device Class = “prtr”) as defined in ICC.1:1998-09, ICC.1:2001-12, ICC.1:2003-09 or ISO 15076-1:2005 and shall be interpreted as representing the intended printing condition.
> 
> ICC spec (7.2.5) identifies 'prtr' as an "Output Device" profile.  So if you really do an RGB-based output device, then you could have a 'prtr' profile for it - but I am not aware of any in actual use.

I'm really confused. Every single desktop inkjet printer comes with such profiles. Every respected paper manufacturer in the photography market produces such profiles for their media for various models of Epson, Canon and HP printers. All such RGB output device profiles are class prtr. There are millions of them. More than CMYK I would guess, because custom CMYK profiles for presses are a.) rare and b.) the standards bodies, esp FOGRA have put in much effort into standardized output conditions.



> I ask this because somewhere I was given the distinct impression that PDF/X-3 does allow RGB OutputIntents, in which case objects could be /DeviceRGB. 
> 
> IF you had an actual RGB-based OutputIntent, that is true - but not in actual practice.

But that's exactly what's being used by Photoshop and Lightroom, and dropped into the Mac OS PDF print spool file as an OutputIntent. It's an RGB-based OutputIntent. All of these desktop printers are treated as RGB 100% of the time when driven by the manufacturer's print driver.


Chris Murphy
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