Re: [idvusers] ISL script examples please? (and dreams)

Don Murray wrote:
Hi Brendon-

Thanks for this information.  Hopefully it will help others along.  A
couple of questions/comments:

- did you have to install the old Java 3D library to get this to work
with Xvfb?  Kevin Tyle has been looking at this for supporting the IDV
image generation in RAMADDA, so if you've found a solution without that,
we should chat offline.

I believe I used the "legacy" Java 3D library during the IDV install process as recommended by previous users. Nothing else special...

- You could do the annotation in ISL as well - it supports image and
text overlays with the <overlay> tag.  You can control the font and
background color of the text.  Is there a reason you are using convert
instead?

We use convert to caption much of our other image generation from Gempak, so it was easier to recycle existing code.

- you can also create animated gifs with convert using the -loop option.

Generating gifs (or animated gifs) didn't work with idv + Xvfb, only png.

Another issue was a limitation based on our mapwall configuration. Previously, we used Imagemagick's "display" command for showing imagery on a screen with the "-window root" option (clean, full screen image without window borders). This works fine with older flavors of Linux that treat a quad-head graphics card with multiple monitors as separate screens (0.0, 0.1, 0.2, etc). Newer versions of Linux treat multiple monitors as one big screen, so an alternative was needed. I'm now using "feh" to display individual images in a multi-screen environment. It allows you to set exactly on your "screen" where you want the image by specifying a size & offset using the -g option. Based on our setup, feh worked better with individual gifs than animated gifs.

Cheers,
Brendon

As Jeff McWhirter used to say - ISL is the most fully documented code in
IDV. Glad you found it worked for you.

Don



On 8/28/13 6:31 AM, Brendon Hoch wrote:
Brian,

I've attached an isl script, shell script, and bundle that I've been
using for the past few months to generate a real time satellite imagery
loop for our mapwall display.  Some notes:

- We're using Centos 5.8 64 bit with plans to move to CentOS 6.x in the
near future.
- Script is scheduled for generation every 30 minutes at :14 & :44 to
give enough time for satellite images to populate on ADDE servers.
- We're using stock Xvfb for a display buffer.  Xvfb runs all the time,
you might need to create a startup script, which you should be able to
find examples of by searching the web based on your linux flavor.
- Historically, 64 bit IDV has had issues generating gifs with Xvfb.
But, it seemed to work ok for generating png files.  So, I convert from
png to gif using Imagemagick's convert command.  I also use Imagemagick
to add nice labels to the image.  I use gifsicle to generate an animated
gif.
- I haven't tried generating .mov files because our mapwall display
doesn't use them, but the process should be similar.  The ISL
documentation is actually quite good (the hardest part is finding it!)

Hope this helps,
Brendon



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--
Brendon Hoch
Technology Manager
Judd Gregg Meteorology Institute
MSC 48, Boyd Hall 321A
Plymouth State University
Plymouth, NH 03264
(603)535-2818 Fax: (603)535-2723
http://vortex.plymouth.edu/~bhoch