Yosra Rekik, Inria Lille & LIFL, University of Lille1, France
Radu-Daniel Vatavu, University Stefan cel Mare Of Suceava, Romania
Laurent Grisoni, Inria Lille & LIFL, University of Lille1, France
About
Match-Up & Conquer is a simple, two-step technique for recognizing multi-touch gesture input that is invariant to how users articulate gestures, 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 preprocessing step that is specific to multi-touch gestures (Match-Up) that clusters together similar strokes produced by different fingers, before running a gesture recognizer (Conquer). We report gains in recognition accuracy up to 10% leveraged by our new preprocessing step, which manages to construct a more adequate representation 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 input and leading toward the design of more efficient and accurate recognizers for touch surfaces.
Match-Up & Conquer two step technique is distributed under the LGPL version2 license agreement.
If you find the code or dataset useful for your work, please let me know. If you use the code or datasets to report results for publications, please reference the work below.
Multi-touch gestures dataset
The multi-touch gesture dataset contains 22 different gesture types: letters, geometric shapes (triangle, square, horizontal line, circle), symbols (five-point star, spiral, heart, zig-zag), and algebra (step- down, asterisk, null, infinite):
Downloads are available on the bottom of this page:
* The dataset
* c++ code (with QT)
Gestures were collected on a 32 inch (81.3 cm) multi-touch display, 3MTM C3266PW, supporting up to 40 simultaneous touches. The application logged touch coordinates with identification numbers and associated timestamps (x,y,touchId,t).
Overall, the Multi-touch Gestures dataset contains 5,155 one and two-handed, multi-touch, multi-stroke gestures:
16 participants x
22 gesture types x
2.92 variations x
5 executions x
=5,155 gesture samples
Algorithm
We provide pseudocode for the Match-Up technique that runs at every timestamp t during the entire duration of articulation of the multi-touch gesture and delivers key strokes. A key stroke is represented by a cluster of points resulted from grouping together points that belong to similar strokes. Point is a structure that defines a touch point with position coordinates (x, y) and identification id. Points is a list of points. Cluster is a structure that contains a list of Points and an id. Clusters is a list of clusters. dp is the displacement vector of point p between 2 successive timestamps.
Publications
Match-Up & Conquer: A Two-Step Technique for Recognizing Unconstrained Bimanual and Multi-Finger Touch Input.
Yosra Rekik, Radu-Daniel Vatavu and Laurent Grisoni.
Proceedings of AVI'14, the 12th ACM International Conference on Advanced Visual Interfaces.AR: 27%