Imaging solutions with Free Software & Open Hardware

Who's online

There are currently 0 users online.

Subscribe to Elphel Development Blog feed Elphel Development Blog
Updated: 8 min 41 sec ago

The last chance to see us at SIGGRAPH’12

Thu, 08/09/2012 - 03:25
Thanks to everyone who had visited us, learned about Eyesis4Pi and suggested some new applications. We hope you have enjoyed our discussions as much as we did.
We are glad to see so much interest in the Eyesis4π panoramic applications we have demonstrated and we continue to look for collaboration in 3D reconstruction based on our camera calibrated for photogrammetry.

More images from the show:

Elphel at SIGGRAPH 2012

Thu, 07/19/2012 - 15:33
Tuesday August 7th – Thursday August 9th Los Angeles Convention Center, Main Hall , Booth 1058

Elphel will present Eyesis4Pi – high resolution full sphere stereophotogrammetric camera at SIGGRAPH 2012, together with it’s calibration machine. We will demonstrate full calibration process to compensate for optical aberrations, allowing to preserve full sensor resolution over the camera FOV, and distortions – for precise pixel-mapping for photogrammetry and 3D reconstruction.

All Elphel camera users are welcome, current and prospective, as well as parties interested in Eyesis4Pi. Here (booth 1058 – see plan) you can talk to the camera developers, see the calibration process and touch the actual working hardware. There is a number of passes available for exhibition only. Please contact Olga Filippova if you would like to receive one.

Run ImageJ plugins from the command line in Ubuntu

Wed, 02/22/2012 - 20:11

1. Get X Virtual FrameBuffer
sudo apt-get install xvfb

2. Launch ImageJ (“cd” to the ij.jar directory):
Xvfb :15 &
DISPLAY=:15 java -Xmx12288m -jar ij.jar -run "TestIJ Plugin"

Comments:

  • TestIJ Plugin is the name of the compiled plugin in the ImageJ menu. No need to specify a subfolder.
  • :15 is an example.

Links that helped:

  1. Source 1
  2. Source 2
  3. Source 3

HomeSide 720° – A helmet mounted panoramic camera

Wed, 02/22/2012 - 11:21

Seeing the impressive images of the Elphel-Eyesis 4pi camera I thought it’s time to tell you about the HomeSide 720°. Like the Eyesis its purpose is to capture panorama frames with a framerate of 5fps. The major difference is that the HomeSide 720° is mounted on a helmet. To have an acceptable weight it consists of only two instead of eight Elphel 353 delivering one forth of the resolution the 4pi does. Thus the camera is able to record 30MPix frames before stitching. Additionally it’s reconfigureable to enable HDR panorama frames.

More interesting probably is the purpose it was built for. We created the assembly for indoor virtual tours. After several drawbacks we finally have an approach which works very well. We do auto leveling, auto stabilization and path extraction by image analysis only. Furthermore we recognize crossing points where the user can decide where to go when the tour is shown in the player.

This is not so easy since we neither have GPS nor IMU data. Nevertheless its possible.

All this information goes into our new webplayer which reassembles the images to a virtual tour.

Have a look at the HomeSide 720° Virtual Tour
Click into the player and use the cursor keys to navigate. You may also click and drag to change the point of view.  This tour was recorded with 10MPix i.e. one Elphel 353 with two sensors.

Important: The pi symbols shows a rendered tour, not recorded by the camera

At the moment we are improving the image quality. We are also looking for a partner to drive the development even faster to create stunning indoor virtual tours.

Introducing the River View Web Player & Other News from River Studies

Fri, 02/10/2012 - 06:27

It has been a long while since my last blog entry in regards to river view panoramas. In the meantime the recording setup runs basically stable (putting aside minor problems with loose connectors) even under rough conditions (see also the gallery “Making Of” at the end of this post).

I just came back from artist-in-residency stays in Varanasi/Benares and Guwahati in India, that enabled me to have a few extensive recording sessions on various vessels like house boats, motor and rowing boats on Ganges River – for one the most sacred river to Hindus and probably most worshipped river on the planet, next to being one of the most polluted rivers of the world – and Brahmaputra River in Assam.

Many thanks go to Kriti Gallery in Varanasi and the Periferry project in Guwahati for hosting me and helping me to get onboard.

Web Player

Meanwhile I also just finished the “River View Web Player” as a public online Beta Version. It runs on openlayers and geodjango and features the growing archive and collection of river views (up to now including views of Ganges, Brahmaputra, Danube and Nile River). There are still plenty of things to polish up, some image material to be retouched and/or uploaded, but see yourself here:

River View Web Player

Using Elphel

I am using an Elphel 353 equipped with 8 or 16mm movie lenses from the seventies to acquire this imagery. The camera delivers a Window-of-Interest video stream of 2592 x 48 pixel size with a variable frame rate between 1 and 300fps (changed on the fly according to the speed of the vessel and distance to the object of focus. That is done manually and under visual control: similar to the auto-focus mechanism, it is also a question of choice and decision and therefore not easily automatable).
The video stream is then processed and saved by custom software.

I am not using Elphel’s internal linescan/photofinish for now, since it still behaves pretty unstable and unpredictable when changing parameters like TRIGGER, VIRT_KEEP and VIRT_HEIGHT on the fly. Also, having a line per frame allows me for a more fine-graded control and preview as long as enough frames are delivered.

Elphel’s internal linescan mode, however, works quite well and stable if it runs as fast as it goes or once you have fixed a setup – as some testing on Austrian Highways prove (find more here):

Elphel 353 in Linescan mode on Austrian Highway A1 - approx. 120km/h, 2000 lps

Sources

The source code of both, my recording software malisca and the web app and player, are open on my github repository.

Making Of / Gallery

A brief guided tour to Ganges and Brahmaputra river recordings in pictures:

On Ganges

Elphel on Ganges River

river recording setup: Thinkpad, Elphel 353, battery pack and USB-GPS-receiver

another shot of recording setup (including an improvised tent)

.. staring into the lens ..

.. obstacles (pontoon bridge) ..

lunch break on Ganges River

Elphel on Brahmaputra River

Not yet, but I would love this setup to be powered by solar energy ....

Pages