What does mean LOSSY indication

[hilario]

I think this is related with the compression JPEG 2000 but I want to understand fully what it means, and why it is indicated if everything is compressed.

[justin]

Hilario,

By default the OnePacs Gateway compresses images using 10:1 JPEG2000 lossy (irreversible) compression. With lossless compression we typically only see about 3:1. The main benefit of lossy compression is faster transmission times because of the smaller file size. Also, there is no perceivable difference in image quality at a reasonable level of compression for most modality types. See http://www.springerlink.com/content/u5r85r66341318w1/ for more information.

Also, if you are using OnePacs as an archive, or have other circumstances that require lossless compression, we can configure your account to use only lossless compression.

Thanks,

Justin

[hilario]

Is it possible to configure different compression for each type of study?
What do you suggest if the majority of our work are CT and MR but we have a 5% of mamografies? Any way to mix the best of both tools?
Is the configuration done at a Gateway level or is it at your Side level?
Thanks

[justin]

Hilario,

By default, the Gateway uses lossless compression for Mammography and lossy for everything else. Is this sufficient?

Thanks,

Justin

[hilario]

That means we don't have anything to modify then, if just mamographie as to be lossless.
There are other studies like "densitometries" (I think this is how they are called). where we also need lossless.
Would it be possible to configure it as lossless?

[justin]

Hilario,

I'm not sure I know what "densitometries" are, but if they can be identified by either modality type (ex. MG, CT, MR) or sop class uid then we will be able to configure the gateway to use lossless compression. Let me know via email and I will set this up for your account.

Thanks,

Justin