Add JP2 support

[denis-rossati]

Aiming for a broader functionality, it would be useful to add jp2 support.

[denis-rossati]

I'll try to make it possible if it is okay for the mainteiners. But in case someone else wants to implement this, here is a base64 encoded .jp2 image:

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