This paper uses a simple method for representing motion in successively layered silhouettes that directly encode system time termed the timed Motion History Image (tMHI). This representation can be used to both (a) determine the current pose of the object and to (b) segment and measure the motions induced by the object in a video scene. These segmented regions are not "motion blobs", but instead motion regions naturally connected to the moving parts of the object of interest. This method may be used as a very general gesture recognition "toolbox". We use it to recognize waving and overhead clapping motions to control a music synthesis program.
Gary R. Bradski, James W. Davis