Taking advantage of my recent acquisition of a Playstation 3 (I should write about it in a near future since I have high expectations regarding its Power Cell), I bought also the PS Eye camera, since the specifications are perfect for multitouch, and most importantly, it is really affordable (considering that a camera with similar characteristics having good performance for MT is around 300€ and not easy to find).

Sony PS3 Eye:

• 4 input audio channels: 16 bits/per channel, 48kHz, SNR 90db
• FOV: 56º o 75º
• 60 fps 640x480 or 120 fps 320×240
• Uncompressed video, JPEG compression

60 fps is just what we need for smooth blob tracking, but we can get up to those 120 if we want extra smoothness, at the cost of lower resolution and higher cpu requirements).

The problem with this camera is to make it work on a PC. I was about to start writting a driver for Windows, but then I found that the great AlexP from NUI Group just published the first functional driver for the PS Eye (and therefore I have saved the work). Still needs some tweaking and a wrapper for touchlib, but soon we will have something stable.

For the moment, I have already removed the IR filter from the camera, and will use a veiled photographic negative, or an internal floppy disk as visible light filter. Thus the camera only capture infrared light instead full image; ie, only blobs of infrared light reflected by fingers on acrylic, which will then be analyzed with Touchlib (though probably I will write my own libraries based on OpenCV to fit y needs).

As for my prototype, I already made the wiring, and will soon post some pictures of it.