Experimental Physics and
Industrial Control System

"Cobb, TM (Tom)" <[email protected]> · Mon, 20 Jul 2009 16:18:46 +0100

Hi,

Our solution is to use an mjpg server, and do the false colour on the
server side. This allows a wide range of clients (web browsers, media
players, and our own custom qt applications) to view the stream. It is a
bit more processor intensive as the stream needs to be compressed and
decompressed, but it saves quite a bit of network bandwidth. It is
packaged as an areaDetector plugin, but feel free to rip the (very
simple) false colour conversion out of it to use in your own
application.

You can download mjpgServer from here:
http://controls.diamond.ac.uk/downloads/ under "EPICS support modules"

Many thanks,

Tom Cobb,
Diamond Light Source Ltd.
Diamond House
Harwell Science and Innovation Campus
Didcot
Oxfordshire
OX11 0DE
United Kingdom
Tel +44 (0) 1235 778582

> -----Original Message-----
> From: [email protected] 
> [mailto:[email protected]] On Behalf Of Matthieu Bec
> Sent: 17 July 2009 20:48
> To: Emmanuel Mayssat
> Cc: epics
> Subject: Re: pseudo coloring of video stream
> 
> 
> Hi Emmanuel,
> 
> We use the same solution. Our selection went to yorick that 
> allows processing the data and comes with a very fast 
> graphics package. That let us handle the rate we get out of 
> our server (~22kB/frame at 30+ fps)
> 
> here's a link to yorick:
> http://yorick.sourceforge.net
> 
> Matthieu
> 
> 
> 
> On 07/17/09 14:56, Mark Rivers wrote:
> > Hi Emmanuel,
> >
> > For my new EPICS areaDetector software the video stream is 
> delivered 
> > via an EPICS waveform record.  There are several other records that 
> > describe the frame size, data type, color mode, etc.
> >
> > I've written a plugin for the ImageJ open-source Java 
> application that 
> > displays this video stream.  ImageJ has lots of nice features, like 
> > the pseudocolor you are asking about.  It also has dynamic line 
> > profiles, showing the intensity of a line cut through the 
> image data 
> > that updates in real time, the ability to capture frames into a 3-D 
> > buffer for playback as a movie or stills, etc.
> >
> > The EPICS + ImageJ solution can display more than 50 frames/sec at 
> > 640x480 resolution.
> >
> > Mark
> >
> >
> > -----Original Message-----
> > From: [email protected]
> > [mailto:[email protected]] On Behalf Of Emmanuel Mayssat
> > Sent: Friday, July 17, 2009 1:51 PM
> > To: epics
> > Subject: pseudo coloring of video stream
> >
> > All,
> >
> > This is not directly related to epics, but rather to operations of 
> > control system.
> > We are using a video stream of 640x480 black and white.
> > Operators are interested in the intensity of each pixel. This 
> > information is used for diagnostics.
> >
> > The human eye being more sensitive to colors than to shade 
> of gray, I 
> > would like to implement a pseudo coloring algorithm. That is filter 
> > the video feed (real time) and map pixel depth to a color table.
> >
> > Is anyone using this?
> > (very common for laser commissioning I was told) If so, let's talk!
> >
> >
> > Regards,
> >
> > Emmanuel Mayssat
> > 650/793-0626
> >
> >
> >
> 
> 
> -- 
> Matthieu Bec              Gemini Observatory
> Tel: +56 51 205785        c/o AURA, Casilla 603
> Fax: +56 51 205650        La Serena, Chile
> 
-- 
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System