Estimating the Difficulty of Touchless Hand Gestures

As part of a Natural User Interface we can use human body gestures, although they must be evaluated to get better results. We can evaluate them using a quantitative model. For this purpose, we begin the analysis of touchless hand gestures based on significant gesture features. From the large number of possible features we selected the length and the directions of trajectory. We propose to use the quantity of distance units and directions for describing and quantifying gestures. Moreover, we found that well-defined changes of directions (or corners) influence the speed for performing a gesture, thus users need more time to execute the gesture. Additionally, a model was developed using these three features. The model allows estimating the difficulty of gestures before users testing.