[Gegl-developer] Image meta data

[Daniel Rogers <daniel@xxxxxxxxxxxxxxxxx>]

It may be worth to consider a way of passing image meta-information 
through the graph.  I am very much not sure about the best way to 
achieve this.

If it a good idea for this to remain in the consumer/producer paradigm, 
then image readers could have a producer that produces a collection of 
objects (name-value pairs?) that describe all the meta info.  It should 
be broad enough to cover all common attributes, so it can be fairly 
file-format neutral.  (then, of course, include the associated consumer 
in file readers).

I think it should mostly be beyond the scope of gegl to handle this 
stuff.  It would be a good idea for gegl to provide hooks to the 
information though, so that other services (external to gegl) can handle 
the problem of what kind of meta-info should be written to files.

To say another way:  gegl should provide access to this information in a 
way that hides details of the file format as well as hooks to read and 
write the information to files, but should _not_ provide a means to 
change that information.  I don't think that changing the information is 
suited to the directed-graph model of processing, and I don't want to 
push gegl's range of features into areas best handled by other parts of 
the gimp.

--
Dan