JPEG 2000

[canonrad]

I see that the latest version of dcmtk has support for JPEG2000 TS, but I don't see any associated codecs. Over at OsiriX we are moving more of our DICOM code to DCMTK and I was wondering if anybody has stable codecs they would be willing to share. I have heard of reports of problems with Jasper. Has anyone tried the OpenJPEG. I have access to kakadu but since OsiriX is open source I can't use it in the project.

Lance

[Michael Onken]

Hi Lance,

correct, in the public toolkit, there are no implementations of JPEG 2000 codecs. However, we've got a private JPEG2000 module based on Jasper, that can be purchased as a module for DCMTK (source code). I guess Osirix doesn't want to spend the money, but if you're interested in an evaluation version for linux or windows (binary), send us an email to NOdicom@SPAMoffis.de. The module integrates just like dcmjpeg into DCMTK and contains compressor/decompressor code.

Perhaps Marco can give you some hints concerning JPEG2000 libraries; we've choosed Jasper and it works fine with DCMTK.

Best Regards,
Michael

[Marco Eichelberg]

Our implementation is based on JasPer, but I had to add a number of modifications to make it work for images with more than 8 bits per sample. OpenJPEG to my understanding is (at least loosely) based on JasPer, seems to also have fixed the issues in JasPer, but I have seen a number of postings indicating that performance-wise it is even slower than JasPer. I have not tried that, though.

[canonrad]

Our built in JPEG 2000 code uses Jasper and I had problems with signed 16 bit data. I would be interested in your code, but I'm not sure how to deal with its propietary nature given that OsiriX is licensed as Open Source.
Lance

[canonrad]

I tried to email this address NOdicom@SPAMoffis.de but it bounced back.

Lance

[Colby Dillion]

We beat our heads on getting JasPer to work with 16bit images for about a day before we gave up and went to OpenJPEG. Other than being a touch slow OpenJPEG has worked very well for us (aka. no changes to the library required). On-the-fly transcoding of CR images is definately not recommended (it is much faster to send them uncompressed on the LAN) and even large sets of CT images (1000 slices is not uncommon for us) require some server power (and a few good luck charms).

If anyone is willing to share some "fixed" JasPer code and codec we might be willing to swap for our JPEG-LS codec. All we got out of trying JasPer was a wasted Monday, but there are plenty of those around here anyways.

[Michael Onken]

@Lance: Here you can find the email adresse without obscurification

Contact to DICOM@OFFIS

Regards,
Michael

[canonrad]

Colby,

Any chance you would share the code you used to implement openJPEG?

Lance

[Colby Dillion]

Lance,

Sorry I didn't get back to you sooner, I was in the process of moving to a new apartment this weekend.

It is a possibility. I will have to speak with the other people involved with that code and I am on a business trip until next Tuesday. If I get terribly bored this week between meetings I might rewrite our codec and "donate" it to OsiriX as it is a project I have been following for a while now. Currently our version does not support multi-frame images as it is not something we needed at the time and as far as I know it only runs on Win32. We are using it in a CR running XP Embedded and has not been tested on other operating systems.

Colby

[canonrad]

Colby,
Talk it over. If possible it would be great.
Lance

[Colby Dillion]

I've been a bit overwhelmed with work lately so not much time to work on extra activities and I try not to do too much "work" after hours.

I did order myself an iMac the other day, maybe that will get me motivated. ;)

[canonrad]

I'm not in a great rush. We already have some JPEG 2000 support. I was hoping to integrate it more seamlessly with dcmtk, but I have plenty on my plate right now.
Lance