IngestTranscoding with lossy J2K not working

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1

Hi everone,

I have been playing around with the different transfer syntaxes available and realized that for jpeg2000, the different syntaxes 90-93 result in identical, rather large filesize. So it seems that all images are compresses lossless. I compared the file sizes to those compressed with weasis and they match exactly with syntax 90 of weasis, so lossless jpeg2000 compression. Am I missing some additional configuration option to enable lossy j2k compression? Already tried the ORTHANC__DICOM_LOSSY_TRANSCODING_QUALITY in my orthanc.yml, but this has only an effect on regular jpeg compression (syntax 51).

Thanks for your insights and advice,
Kind regards,
Ruediger

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Hi Rüdiger,

I can confirm that, right now, Orthanc has no configuration option for j2k lossy compression quality.

Best regards,

Alain.

3

Hi Alain,
thanks for your reply.
I’ve realized that J2K lossy is anyways not so good for cardiac MRI, especially the cine sequences are quite blurry even at low compression levels.
So I’ll stick with near lossless jpeg-ls (syntax 81), that’s a good trade-off between quality and compression (with mixed images 1:4).

Kind regards,
Ruediger