progressive images not supported about cl-jpeg

[knobo]

At least for reading.

[varjagg]

I know - it's actually the only item on TODO, the bottom of README.md. It's a fair bit of change though, I'd really like to do it in one sitting over few days but so far never had the time. Hope I can look into that during the summer.

[knobo]

I don't know if I'm right, but I suspect there are two ways of doing this. One is to decode progressively while reading. Another way is to read the whole file, then convert it to something that can be decoded as if it was a baseline image. And if I'm right, would it be easier to do it the latter way? Maybe so easy that it could be done in one day, instead of few days?

[varjagg]

No, it's pretty much the same, the "convert it" part is the progressive decoding.