DiamondTouch: Multitouch and Multi-user

One of the biggest problems with multitouch systems - usually encountered with larger table top and wall mounted systems - is distinguishing between the touch of different people.

The classic example of this problem, one that I encountered myself, are paint applications. In a collaborative multitouch situation, because the multitouch device cannot distinguish between different users, all users have to use the same color at the same time if working on a communal canvas. User A can't be working with red while user B is working with blue if they want to annotate or color the same area at the same time.

The DiamondTouch addresses this classic issue by making the users a physical part of the capacitive touch detection system. When a user touches the table the current (very minimal) is actually routed from the antenna array under the table though the users body to the computer. To make this work each user has to have their own receiver which might be a wrist band or a conductive pad on their chair. Since each user has a unique receiver the multitouch system can determine who is touching the screen where and so each user can operate on the same canvas with different output. I don't know if that makes much sense as its hard to explain but the web site of the company that licenses DiamondTouch provides more explanations.

DiamondTouch was originally developed by researchers at Mitsubishi Electronic Research Laboratories (MERL) starting in 2000 and was just spun off under a new company, Circle12. The device can be used with standard windows via a mouse emulator and no programming, but Circle12 also provides their own DiamondTouch SDK which supports development in C++, Java, or ActiveX as well as a Flash-based SDK called DTFlash.

The thing I don't like about DiamondTouch, and its something Circle12 is working on, is the fact that the device is front projected. That said, I really like the ability to distinguish between different users touching the same content area. I think this is a big hurdle to collaborative multitouch applications. I also like the resolution of the DiamondTouch which can be as high as 2752 x 2064 or video while allowing users to manipulate points as small at 0.3mm in diameter - no other multitouch system I know offers that level of granularity.