Experimental Physics and
Industrial Control System

"Smith, William via Tech-talk" <tech-talk at aps.anl.gov> · Mon, 22 Nov 2021 18:58:20 +0000

Cool, if I find time I will give this a go and raise a pull request. Thanks Mark and Kay for the help (again!!)

Will

-----Original Message-----
From: Mark L Rivers <rivers at cars.uchicago.edu>
Sent: Monday, November 22, 2021 7:12 PM
To: Kasemir, Kay <kasemirk at ornl.gov>; Smith, William <william.smith at helmholtz-berlin.de>
Cc: EPICS Tech Talk <tech-talk at aps.anl.gov>
Subject: RE: Phoebus Image Decompression

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 at aps.anl.gov> On Behalf Of Kasemir, Kay via Tech-talk
Sent: Monday, November 22, 2021 11:33 AM
To: tech-talk at aps.anl.gov; Smith, William <william.smith at 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

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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System