RE: Phoebus Image Decompression

[Mark L Rivers via Tech-talk <tech-talk@aps.anl.gov>]

There is Java code to decompress all of the supported areaDetector codecs in NDPluginCodec in ADViewers.
https://github.com/areaDetector/ADViewers/tree/master/ImageJ/EPICS_areaDetector

These are just wrappers around the C/C++ codecs in ADSupport which are built as shareable libraries.

Mark

-----Original Message-----
From: Tech-talk <tech-talk-bounces@aps.anl.gov> On Behalf Of Kasemir, Kay via Tech-talk
Sent: Monday, November 22, 2021 11:33 AM
To: tech-talk@aps.anl.gov; Smith, William <william.smith@helmholtz-berlin.de>
Subject: Re: Phoebus Image Decompression

Hi Will,

> Does Phoebus image viewer work with area detector compressed images sent over PV access? I.E can it read the compression type from the PV access protocol and perform the decompression?
 
At this time, regrettably, no. The relevant code is in https://github.com/ControlSystemStudio/phoebus/blob/master/core/pv/src/main/java/org/phoebus/pv/pva/ImageDecoder.java

In principle, it's straight forward to add something like `struct.get("compression")` to determine how the data is compressed, and to then un-compress the `value`.
If you have some actual test data and information on how to decode the compressed image, please go ahead and implement it.

Thanks,
Kay