[CREATE] OpenRaster fallbacks (proposal/RFC)

[Martin Renold]

On Wed, Sep 02, 2009 at 10:12:48AM +0200, Cyrille Berger wrote:
> That sounds like a bug in Krita, it should be able to open it at 16bit, or 
> maybe it's just that the main image is always marked as RGB 8bit (very likely) 
> and the layer is actually 16bit, do you have the file so that I can check ?

http://mypaint.info/misc/16bitpng.ora

> Now that I think of it, I seems to remember there is a function in libpng that 
> always return a RGB 8bit image (whatever the original image is, 8/16bit RGB, 
> grayscale, indexed). It's very possible that MyPaint use that, and DrawPile 
> doesn't.

Sounds very likely.

> But if there is that API, we can as well says that the fallback can be any 
> kind of PNG, and people who only support RGB 8bit would be advised to use that 
> API.

That doesn't sound so bad then. If we choose to make this official, then we
should offer a kind of "compatibility test suite" of ORA files for
developers to check against, as this case is easily overlooked.

> On that point, I am not too concern about those breakage, I think that 
> OpenRaster goal is interoperability, but if that goal can only be achieved in 
> a year, it's not a big problem for me (as long as we communicate on this). So 
> what it is important is that mypaint keeps being able to open old files created 
> with older mypaint.

There is a GIMP plugin being written, and I recently got mail from someone
who wants to try implementing full-screen previews in a file browser (gloobus).

I hope we can make only one breakage, and after that applications should be
able to add as much compatibility as they think is still required when saving.

bye,
Martin