I just got mine going last night.  for those of you with darker rooms, I combated the dim basement with a row of christmass lights surrounding the box(just above the paper) This works very well, looks very ghetto but works well.

cerupcat - 22 May 2008 10:48 PM

@ Theonlymac001: Have you tried the method mentioned in the Getting Started guide and using graphedit that’s included in the MTmini package?

Yes i tried graphedit but to be honest i dont really know what to do with all those fancy characrers i added a filter for “mobiola video source” and i addad this to the configxml or whatever. soo either i’m so crap i dunno what to do orr… erm. or this just doesnt work but it must ‘cos there are videos of nokia phones. so.. any further idea? thanxx for your fast reply though

It’s case sensitive! the name MUST be exactly the same

I’m new here and I built my touchpad today, but I’m having some problems with it. How tall should the box be? mine is about 35 cms
the “background remove” screen removes EVERYTHING so there is nothing on the 4,5 and 6 windows. I came to the conclusion that it’s a problem with the webcam, it’s really cheap and the input is in RGB without compresion, so there is A LOT of noise there (A LOT!). Is there any way to fix it? I can’t find any program to filter the image to get a better quality
(like subtracting the dark noise on real time: http://aggregate.org/DIT/peepfish/ <- info about this, it would be great to have something like that on my webcam)

I tried with my MP5 (wich can be used as a webcam) and everything worked fine… but I can't get the "sweet spot"… it works but I don't need to touch the paper because a lot of points start to apperar… any suggestion? wich kind of paper are you using? I think that my box is too tall.
this is a screenshot of my working camera:

But the mouse jumps from one side to another.

Any suggestion?

Thanks for your time! this project is great!!

The box size shouldn’t matter. The bigger the box, the bigger the touchpad. The minimal size should be an area where the camera can only see the surface (not the sides of the box). For your image, you either don’t have enough light in the background or you need a different kind of paper. I’m using normal printer paper in the video. You’re getting shadows of your whole hand, where you should be getting more contrast where your fingers are. Even a cheap camera should work. It seems the biggest problem is either your lighting environment or your paper. If you can get good shadows where your fingers are, you’ll get good blobs in the final image. And yes, background remove should remove EVERYTHING from the windows after invert.

As for the mouse, it’s not very stable. A new mouse driver will be released soon.

yes i did write it with capital letters at start of each word.. It might be the problem that it doesnt like spaces so i will try _ and see what happens. And waiting for the new mouse driver by the way i translated the instructions to a few languages so that should spread the thing :D
Just one more question. Do i have to change anything in the config.xml file or is it just the dvl_config? And it also says the picture resolution beside the friendly camera name. Is that a problem he it isn’t the actual resolution of my cam? Cheers

This seems pretty simple to make compared to a proper MT table. I guess I’ll give it a try.
Is it necessary to have a box with its length and breadth in a 4:3 ratio?

Hey i am useing a laptop with a built in webcam. I have created my MT mini, but when i use it i just get the webcam that is on the laptop. Anyway to fix this?

YESS!! i finaly got it working i think it was just my computer that wasnt working i reinstalled windowes and it works now

but i have a Question how do i get the flash apps to work like the pong and photo thing i can see it but i cant manipulate anything in it help plz

*Cant manipulate

** NVM I got it working !

I have a microsoft lifecam vx-1000 and I can not make it work program, I get the gray screen, and I do not show anything, what’s the problem?

anubseran - 28 May 2008 11:40 PM

This seems pretty simple to make compared to a proper MT table. I guess I’ll give it a try.
Is it necessary to have a box with its length and breadth in a 4:3 ratio?

no, i made mine with a round plastic bucket instead of a carboard box, which worked fine too.

Hallo!

I made a minimt today. Works great!
But in the apllications only the left, top quarter of the window is regocniced.
Can I scale it to the complete screen? I’m using a Sony Eye Toy cam.

Greetings from Germany

hensch, in order to fix that, in configapp.exe hit ‘enter’ and go through the calibration process (Instructions are on screen).

Here is a suggestion for a different setup.

I tried to build an MT Mini by your instructions, but got quite dissatisfied with the result. First of all, the manual goes mainly for Windows. I figured how to build touchlib for Linux, but the final running program wasn’t showing the same windows and kind of missing stuff. I fired up Windows and did everything there. Although the table worked, I immediately noticed two shortcomings:

a.) Illumination requirements are picky. It works only best if the light is scattered across the room so the shadows become blurry as soon as the finger is not directly touching the surface. I have halogen lamps in my room, so that’s a real problem. I tried covering them a bit, but then the light becomes too dark for the camera to see enough.

b.) If finger shadows overlap, there is a problem. This is also part of a.). If the light comes more from the side, some finger shadows overlap, you have to constantly watch how you spread your hand and move your fingers. Not every constellation works.

Additionally I have to say that controlling the desktop is also problematic, since the surface I am controlling is somewhere else than the surface that is being controlled. Of course this one is obvious.

So it got me thinking how to improve the setup and fix some of the issues. I think I found a much better solution that requires also only a Webcam, two cardboard frames, some LEDs and excessive amounts of tape, although I wanted to validate this idea with you before I seriously start making a plan.

1. Cut out two cardboard frames so that they match the size of your computer screen. The frames borders should be wide.
2. Like with the big MT table, place LEDs between the frame borders at the top and at the bottom, away from the inward border, so that when you place a piece of paper inside the frame, the light cast by the LEDs casts a hard shadow which seems to divide front and backside of the frame.
3. Place the frame so that it hovers in front of the screen, at a distance of say 10cm, although more is usually better.
4. Place the webcam high above and a little bit behind the screen so it looks at the back of the frame.

Now when you put your fingers through the frame, your fingertips will be illuminated - this corresponds to a touch. The camera can clearly distinguish an illuminated fingertip from the background. The image has to be perspective corrected before being processed, of course, and the vertical resolution will thus be a bit lower than the horizontal one.

The result is that you can turn your screen into a touch screen this way - the less distance the frame has to the screen (which requires more perspective correction and lowers the vertical resolution even more), the more it becomes a touch screen.

I think you could also use infrared light here - even a glass window, like in the big table.

It’s just speculation but I think I made no mistake. Please let me know what you think

Hey I have a question about the MTmini. I haven’t started this project yet, but I want to know how the basic controls work. Is there a way to change them? Because I would want to make them a little more customizable. Like a normal click would be a single tap, and the click would come on the release. And instead of when you press the finger and drag it, it act like the mouse action of clicking and dragging, it would just have the cursor follow your finger. No dragging. And to make something drag, you would like double tap and on the second tap, begin dragging. This is because with out it, I would have no idea of where the mouse is on the screen, without accidentally clicking something or dragging something. In other words, by default, is there any way to simply move the mouse without also clicking it. Thank you.

@ III Icon III: THere’s a new mouse driver located here: http://nuigroup.com/forums/viewthread/2465/ It does some of the things you’re looking for. There’s also a trackpad version that’ll move the mouse similar to a trackpad on a laptop.

@paniq: Yeah sorry. The package is mainly for windows since touchlib mainly works on windows. That’ll be changing soon though. Yes lighting requirements are fairly picky although once you find a lighting environment that works good, it’s not too hard to replicated it. Placing a small lamp by the MTmini can help. If the tips of the fingers are more distinguished than the shadows of the hand, the touchlib filters can filter out the shadows easily. Also, we just released a new mousedriver for controlling the desktop. There’s a trackpad mode that helps a lot. I don’t completley understand your ‘fixes’ but from the overall sound it should work. I sounds like the same technique used in microsofts laser technique and also some people here who are using front illumination/lasers. I say go ahead and try it out. Keep in mind, if this is something you want to have others try, the reason I went with only using a camera and no extra components (no LEDs) is because most people won’t try something like this unless it’s incredibly simple which requires steps that don’t involve powering anything or soldering. I like your idea though and think you should totally try it out! =) Let us know how it goes.