POMDP models for continuous calibration of interactive surfaces
Bastian Migge, Schmidt, Tim, Andreas M. Kunz · 2010
corresponding author On interactive surfaces, an accurate system calibration is crucial for a precise user interaction. Today, geometric distortions are eliminated by a static calibration. However, this calibration is specific to a user’s posture, and parallax distortions occur if this changes (i.e. if the user moves or if multiple users take turns). Within this paper, we describe an approach to model automatic online re-calibration to cope with changing viewpoints by using Partially Observable Markov Decision Processes (POMDP). Hereby, the viewpoint is stochastically deducted from the precision of user interactions on the surface. To enable the implementation on embedded systems, a small model is defined using states and observations, which are formulated relative to the current assumed viewpoint. We show the structure of a family of models, that can be generated automatically based on the user’s position probability and pointing accuracy. distances of a few millimeters between image plane and interaction plane can cause enough optical distortion to significantly impair the user interaction (see Figure 2). This also holds true for back-projection systems. The possibility of distortion increases with the size of the screen and the distance between image and interaction plane (Vz) as shown in Figure 3. The distortion depends on the distance between the viewpoint and the point of interaction, as well as on the viewing angle against perpendicular.