>   Can't you use different compression levels on different parts of the image
> in JPEG2000?

Yes, you can, even in two different ways.
1.) j2k can consist of tiles of eg 128x128 pixels (or whatever dimension you
like)
and the decompressor can be reinitialized (for different quality settings) for
each tile.
2.) The ROI-tag  (Region Of Interest) to store a part of the image even in
higher
resolution.

BUT, none of those nine test images uses any of these features and already
with them you'll find not much reliable software to decode them and with those
*extended* features (but still ISO part 1 standard) the situation becomes
really worse.
I really do not want to advertise this Kakadu thing, but it was the only one
that
did it right.


> > The JPEG2000 file header is just XML
>
>   And I thought they wanted the file to be as small as possible...
>
Well, I do not know how the ISO works...

> > And about the 16bit/8bit per channel color banding controversy. Somehow this
> > reminds me on people who seem to think a 64bit CPU is twice as fast as a
> > 32bit one.
>
>   I wouldn't compare it to that.
>   I would compare it to 16-bit vs. 24-bit sound sampling. A layman does
> not hear any difference at all between 16-bit (eg. CD) and 24-bit sound,
> but professionals would not work with anything less than 24. The same
> goes for 44kHz vs. 96kHz sample rate...

Yes, sure you are right and your example is much better. It was just the case
that a few minutes before writing this I did read a posting where somebody
seriously did say this.

-Ive

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