Match-up & conquer: A two-step technique for recognizing unconstrained bimanual and multi-finger touch input

We present a simple, two-step technique for recognizing multi-touch gesture input that is invariant to how users articulate ges-tures, i.e., by using one or two hands, one or multiple fingers, one or multiple strokes, synchronous or asynchronous stroke input. We introduce, for the first time in the gesture literature, a preprocess-ing step that is specific to multi-touch gestures (Match-Up) that clusters together similar strokes produced by different fingers, be-fore running a gesture recognizer (Conquer). We report gains in recognition accuracy up to 10 % leveraged by our new preprocess-ing step, which manages to construct a more adequate representa-tion of multi-touch gestures in terms of key strokes. It is our hope that the Match-Up technique will add to the practitioners ’ toolkit of gesture preprocessing techniques, as a first step toward filling today’s lack of algorithmic knowledge to process multi-touch in-put and leading toward the design of more efficient and accurate recognizers for touch surfaces