Comment 26 for bug 263661

I think that's what we want to get to, once we get to being able to do decode-on-draw. It's not a great solution right now though, because we don't want to cache all scaled images since they can become quite large; you can toss in a limit, and then you're back to having to scale on demand, which means having to keep the original bits around. It also means that if hardware does accelerate the scaling, that we'd lose any access to that; for example, if the native image representation is a GL texture.

But, I think that we should be able to at least partially do it the way you describe... I think the missing piece is decode-on-draw, so that we can better manage memory usage.