Re: [Gegl-developer] babl roadmap: How do you know which images are sRGB images?

[Elle Stone <ellestone ninedegreesbelow com>]

On 10/13/2014 06:36 PM, Elle Stone wrote:
> How do you plan to tell when an image is an sRGB image and when it's not
> an sRGB image?

The roadmap specifies 24 different formats for sRGB images and 24 
additional formats for non-sRGB images.

Presumably the 24 additional formats for non-sRGB images allow GEGL to 
request, as needed, a conversion of the RGB data from being encoded 
using sRGB primaries to being encoded using "User_RGB" primaries and 
vice versa.

Given the 24 additional formats for non-sRGB images, it seems pretty 
important to be able to detect when the user opens an sRGB image and 
when the user opens an image that's in some other RGB working space.

So again, upon opening an image, how do you plan to detect whether the 
image is an sRGB image or not?

Will you compare MD5 checksums?
Will you consult the profile descriptions?
Will you examine the profile colorants and TRCs?

If you don't understand the context of the question, see the following 
article: Will the Real sRGB Profile Please Stand Up? 
(http://ninedegreesbelow.com/photography/srgb-profile-comparison.html)

It should be noted that the article doesn't list *all* sRGB profile 
variants (new ones are being made every day). In particular, the article 
doesn't list sRGB profile variants distributed with Canon, Nikon, etc 
proprietary software.

With respect,
Elle Stone
--
http://ninedegreesbelow.com
Color management and free/libre photography