jp2 quality

[Partha]

is it just me or saving to jp2 format is fixed at 70% quality?

Thanks,
Partha
www.partha.com

[Martin Huber]

is it just me or saving to jp2 format is fixed at 70% quality?

Here in Mac OS the quality slider works fine. I tested Save As and Web Export.
But the slider is disabled, if you turn on lossless compression.

Martin

[Partha]

Hi Martin,

I tried it on Windows. I will repeat on my Mac to verify.

Any reason for the quality issue with lossless compression? I would think that this is jp2's claim to fame?

Thanks,
Partha

[Martin Huber]

Any reason for the quality issue with lossless compression? I would think that this is jp2's claim to fame?

Well, "lossless" is lossless, so there is no need for a quality slider, because the result is always the same as the original.

Martin

[bkh]

Any reason for the quality issue with lossless compression? I would think that this is jp2's claim to fame?

Well, "lossless" is lossless, so there is no need for a quality slider, because the result is always the same as the original.

Maybe a small change in the GUI would make this point clearer?

JP2000 quality.jpg

Cheers

Burkhard.

[Partha]

Any reason for the quality issue with lossless compression? I would think that this is jp2's claim to fame?

Well, "lossless" is lossless, so there is no need for a quality slider, because the result is always the same as the original.

Martin

Good point. I am thinking maybe instead of a separate checkbox, if the quality is set to 100%, it's automatically set to lossless? At least that's how I would perceive it.

Thanks again,
Partha

[bkh]

Good point. I am thinking maybe instead of a separate checkbox, if the quality is set to 100%, it's automatically set to lossless? At least that's how I would perceive it.

Just like JPEG, 100% compression in JPEG2000 isn't lossless (lossless compression uses a totally different compression method). I think it's wise not to mix these things up.

Cheers

Burkhard.