TRACKING OBJECTS ON A TOUCH SURFACE

摘要

A device implements a method of tracking objects on a touch surface of an FTIR based touch-sensitive apparatus. The method repeatedly operates to generate (50-52) an interaction pattern that indicates local changes in interaction on the touch surface, identify (53) apparent peaks in the interaction pattern, and update (54) existing movement trajectories based on the apparent peaks. An error suppression process (56) is executed at least intermittently in the method to process the apparent peaks and/or the existing movement trajectories to identify implicated trajectories with a potential tracking problem, define two or more movement propositions for each implicated trajectory, and cause an evaluation of the movement propositions in one or more subsequent repetitions of the method. The error suppression process improves tracking by postponing the final decision on how to track the object of the implicated trajectory until more information is available. It also allows the origin of the tracking problem to subside and/or the object to move away from an area on the touch surface that exhibits interferences.