[Openicc] Linux CM ideology .. Linux CM proposal

[Chris Murphy]

On Feb 8, 2011, at 8:22 PM, Graeme Gill wrote:

> Chris Murphy wrote:
>> Most people don't search profiles by device though. They search for them by color
>> space. Or by color space and profile class. At least, that's how the UI is presented.
> 
> I'm not sure we're talking about the same thing then. I'm not talking about
> a GUI tool for organizing profiles, I'm interested in a service that allows
> applications that want to use/generate images for a particular device to
> locate a profile that defines the device color space. So by definition,
> profiles are associated with a device.

I understand, but if the application UI presents profiles in a particular way, it seemed to me you'd want your service to present that result to the application so it doesn't have to do such sorting.

If we are talking about default profiles for device conditions defined by the printer PPD using *cupsICCProfile, and then some other mechanism for other devices, that's definitely needed and the implementation of the service can be simple. However if you're thinking of user definable (redefinable or extendable) associations between device conditions and their profiles, instead of a one-time override in an application or print dialog, then there may be more to it than this. 

Simplest case is displays. Build a profile from EDID, set it as the display profile. If custom, the software creating it should set the profile for that device. Users really don't need to interact with this. Apple has two locations for it. Most people use neither. It's handled for them.

Next case, input devices. Scanners and cameras can all render into sRGB and tend to do so by default. So they are done. I haven't built a scanner ICC profile in I can't even remember how long it's been. Years? And that was probably a demo. For cameras, we can go around on the merits of camera profiling. I'm not a fan but then I use a Raw workflow. Absolutely more common than ICC or Raw in this category is EXIF sRGB and Adobe RGB color space tags.

Output devices is the most complex scenario of the three. That's mostly what I think we're talking about. Apple has a tool for users to change the associations of device conditions and their ICC profile (to a custom one for example) and again, I don't use it. Why? Every application I use implements its own color management, and there is no mechanism for me to choose the printer in a print dialog and for the application to be informed what the profile is for that printer, and auto-populate its own setting for preconversion to that profile. I have to manually choose the custom profile for that device, every time I print. Icky? Yes. But even what we have isn't being used by anyone, let alone anything more glamorous.

So I think we need to discuss this with the developers of essentially every graphics and photo tool that users who care about good color and printing are using. And ask them "if we build this thing, will you use it or not? what does it need to look like". Because it doesn't just matter what I think. It's got to be a ubiquitously implemented service. If it's not, users won't use it, even if they'd like to, because only one or two apps use the service.


Chris Murphy