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23” LCD FTIR
Posted: 14 May 2010 02:32 AM   [ Ignore ]
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This thread is about a 23” LCD FTIR multitouch stand that I am building in our research lab with the help of another lab member. I started a discussion on initial ideas which was based on a DI, in another thread but since things changed a lot, I decided to create a new thread to document this project. My main goals are to get a very good touch and gesture recognition as well as being able to rotate and tilt the screen to any desirable angle.

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Daniel in the previous thread gave me the idea of punching a hole through the back light, it worked awesome! I used a 3/4” bit since thats approximately the thickness of the ps3eye lens. 


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I changed my design to a simple box since I am now using the LCD backlight, which is a LED by the way.


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After mounting the back light.


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Firing up the LCD, It works! smile


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After mounting the side door.

So far everything has been working as expected. When we tested the FTIR panel we got very good blobs when touching but when dragging or performing gestures the blobs become much smaller and sometimes are not detected, unless you push really hard on the screen which is not a nice interaction. I will post more updates soon (hopefully tomorrow night).

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Build a Near Touch Device! | Blog | 23" LCD FTIR running Ubuntu 11.04 | 32" LCD DSI Coffeetable

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Posted: 17 May 2010 10:01 PM   [ Ignore ]   [ # 1 ]
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I made some progress since last week and did some testing today. The box is pretty much finished now. Here are some pics:
17MayP04.JPG
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This is what the inside looks like. The ps3eye is mounted under the box and the lense is going through the backlight.

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First thing I tried after hooking up the camera was PyMT. I used reacTIVision for tracking blobs.

mtStand17May2010_01.jpeg
Right now I am having a bit of an issue with the camera. I tried using the lens inside a door viewer to increase the viewing angle of the ps3eye lens. During the process I broke the lens mount and it is really out of focus now. Therefore it is creating a very grainy image resulting in constant false blobs when I reduce the gradient (g) setting in reacTIVision. So I ordered a wide angle lens as well as an 940nm bandpass filter, both of which I am hoping will improve the results significantly.

PyMT gives me something between 30 and 60 fps but reacTIVision shows something like 29 to 31 on average. When I tried running some of the demo apps like the Mandelbrot Viewer the CPU usage went up to the roof and the fps fell down to something like 2~3 in both reacTIVision and in PyMT. Does anyone know why the two fps do not match and if is it normal that some of the demo apps use so much CPU?

I nearly have my first MT project done smile thanks you all for the great support! NUI community is amazing.

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Posted: 05 June 2010 04:10 PM   [ Ignore ]   [ # 2 ]
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Hey

Tthat is AMAZING !

I’m just starting my journey with touch screens but if u can plz tell me… how can camera see through LCD? How does it work ? :s

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Posted: 05 June 2010 05:51 PM   [ Ignore ]   [ # 3 ]
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Hi Dariusz,
Thanks. This was actually my first attempt and if I build another MT table I would do several things differently. But this works quite well smile

If you open an LED LCD you will likely find the following layers in it:

-------------- LCD Image Panel (Semi-transparent) -------------------------
---------------------------- Light diffuser ---------------------------------------
-------------------------- Back-light panel -------------------------(LED lights]
-------------------------- White sheet -------------------------------------------
-------------------------- Metal sheet to hold back-light -----------------------

This might be different in different LCD’s but the basic concept is that the backlight can be separated from the actual LCD and you can put the camera in front of the backlight. The LCD that I used is a LG 23” LED LCD. You don’t have to drill a hole through the backlight like I did but that is an option. The camera can see through the LCD image because that panel is semi-transparent.

Let me know when you start your project, or if you have other questions. Don’t rush into building your multi-touch before you read about the various options in the forum and in the wiki.

Cheers!

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Posted: 05 June 2010 06:23 PM   [ Ignore ]   [ # 4 ]
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Hey Aras

Thanx for ur help ! It cleared alot! smile

And yea I’m not rushing at all smile From 3 weeks I’m googling and googling and tbh my head is going to explode ! It all started from simple Wii controler… and now LCD doh… help ! smile

Curiously would it be ok if u could give me ur msn/skype so I can contact you directly for some help from time to time? I dont want to spam forum with too simple questions heh… smile

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Posted: 08 June 2010 12:03 AM   [ Ignore ]   [ # 5 ]
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No problem Dariusz,
You can PM me if you have a question that you think I might be able to answer. Just so you know, I am very new here as well, but I will try to help when I can. Anyway, people here are very helpful so don’t be afraid to post your questions to the forum, as long as you do some searching around and collect the existing information about your question.

Cheers!

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Posted: 01 July 2010 07:10 AM   [ Ignore ]   [ # 6 ]
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Hey Aras,
Great work...was wondering if you could provide some assistance with getting CCV compiled on Ubuntu 10.04.  I’ve been reading some of your earlier posts..and I’ve come across a road block. 

Before I dive into building a MT Table...I figured I start with a MTmini (cheap).  when I tried compiling CCV and I’m getting a segfault and it seems like the application wants to launch and then rapidly disappears.  How did you solve this issue...again I tried following some of your posts and those who where helping you..Any help would be gladly appreciated.

I can pipe the log file into a text file and post here if this helps.

I’m running Ubuntu 10.04 and I’m actually using a xbox 360 camera for the time being.... I will be purchasing a modified PS3 cam in the near future once I’ve gotten a better understanding of how I want my table designed.

I did however get this MTmini running through Windows...however I rather focus using Linux.

Thanks!!!

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Posted: 02 July 2010 09:16 PM   [ Ignore ]   [ # 7 ]
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Hi Shaolin,
Sorry for the late reply, I have been away for a few days. The issue you are talking about sounds like what was discussed in the third page of this thread . basically, playing the sample video file fails and that takes CCV down with a segmentation file; dont ask me why. Luckily, you can configure CCV to use the webcam instead of the sample video: just edit your config.xml and change the value for “use_camera” attribute from 0 to 1.

If you encounter any other issues let me know. I would suggest opening a thread and describing the problem. I would try my best to help. Good luck and let me know how it goes smile.

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Posted: 04 July 2010 12:46 PM   [ Ignore ]   [ # 8 ]
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Hi Aras!!
Thank you so much for the helpful information..I’ve changed the value of UseCamera from 0 to 1 and it allowed the program to start without crashing...so now I can actually see the interface...however now I’ve stumbled into another problem...CCV is not seeing my xbox 360 web cam.

I’ve made sure I have installed libunicab2

when I click on next camera I get the following:

OF_ERROR: ofUCUtils: Error opening device 86:

and it keeps going if I keep hitting next camera.

Any ideas on this one??

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Posted: 04 July 2010 04:23 PM   [ Ignore ]   [ # 9 ]
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Shaolin,
I dont have any experience with the xbox, so I cant help you much with that. But I wonder, have you tried building the CCV from source code? I was able to build it using code::blocks on lucid lynx. Can you see the camera using cheese or any other webcam tools? Have you tried any other trackers such as reacTIVision? it is a bit tricky to configure but works great in Linux.

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Posted: 05 July 2010 11:38 AM   [ Ignore ]   [ # 10 ]
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Aras,
Thanks for quick reply, I can see the camera through Cheese...I’ve tried messing around with the configure.xml file and adjusting the resolution and FPS and CCV still can’t see the camera.  Wish I had another camera to test with.  But for now I’m going to keep trying to get this going with this camera.

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Posted: 31 October 2010 08:51 PM   [ Ignore ]   [ # 11 ]
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Hi Aras,

can you specify wich lcd model you use?

thanks

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Posted: 03 November 2010 12:14 PM   [ Ignore ]   [ # 12 ]
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@Jmccd,
Sorry for late reply. It is a LG E2350. Which is an LED LCD. Very easy to disassemble. Its very light, has no cable issues. It has a very long cable going to the backlight which is very nice if you want to move the backlight further away from the LCD screen. Let me know if you have any other questions.

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Posted: 28 April 2011 01:37 AM   [ Ignore ]   [ # 13 ]
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Hey I know Melanie. How is your project getting on? What kind of degree are you working on?

I documented my tables and experiments on the following page:

http://www.elvis.ac.nz/Main/Multi-touchTable

Cheers Craig

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Multi-touch Table User Interfaces for Software Visualization
http://homepages.ecs.vuw.ac.nz/~craig (homepage)
http://www.elvis.ac.nz/Main/Multi-touchTable (48” and 28” tables)
http://softvis.wordpress.com/ (blog)

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Posted: 28 April 2011 02:49 AM   [ Ignore ]   [ # 14 ]
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Hi Craig,
Your tables look really awesome! I also found your thesis topic very interesting. I think there is a lot of potential for interacting with software visualisations.

I am doing my masters on hand interaction with information visualisations. I am setting up an experiment to test some gesture based interactions with a few visualizations. I have done a couple more tables since this, I should really do a better job of documenting my work rasberry.

From your website it looks like you are in NewZealand. Are you coming to Canada for CHI by any chance?

Cheers!

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Posted: 28 April 2011 03:03 AM   [ Ignore ]   [ # 15 ]
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Thanks for the compliments. I know a few people from your dept, The Mod Squad (Yvonne) and Chisel Groups (Peggy).

Look up Petra Isenberg who is now at Inria in France but did her PhD at Calgary with Sheelagh Carpendale on information visualization and multi-touch tables.
http://www.aviz.fr/~isenberg/

No CHI for me this year. There are a couple of workshops focused on multi-touch, one about mulit-touch in the wild led by Uta Hinrichs from Calgary along with other people including Sheelagh. Also next generation HCI education interfaces led by Johannes Schoening (DFKI) and Edward Tse (SMART)

I tend to focus on SoftVis / Software Engineering conferences at the moment, plus ITS. Once I get toward the end of the degree I may submit something to CHI. Indeed I am in and from New Zealand.

You should also check out the SurfNet project in Canada where a number of researchers at Canadian universities are actively participating. Especially if you are interested in doing further grad studies or research. The closest collaborator on the project in your neck of the woods is Philippe Kruchten at UBC. As far as I am aware he has some SMART tables you could probably test your applications on. Likewise go to Calgary where most of the principle investigators of the project are located.
http://nsercsurfnet.ca
http://philippe.kruchten.com/

Do you have any publications thus far?

Keep me posted I would be interested to know more. Perhaps via email grin

Cheers Craig

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Multi-touch Table User Interfaces for Software Visualization
http://homepages.ecs.vuw.ac.nz/~craig (homepage)
http://www.elvis.ac.nz/Main/Multi-touchTable (48” and 28” tables)
http://softvis.wordpress.com/ (blog)

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