Patent ID: 6633671
Filing Date: 2003-10-14
Classification: G06F,G06K,G07C

Abstract:
A writing implement touching detector system, comprising:a single image acquisition device, capable of being moved to a plurality of different locations relative to a writing implement, and producing an output indicative of a scene imaged by the single image acquisition device; a processor, responsive to said output from the single image acquisition device, and operating to detect when a writing implement that is in the scene and unconnected to said image acquisition device is touching an associated writing surface, and when said writing implement is not touching the writing surface based on only the output of the single image acquisition device, by using a stochastic model to obtain a probability that the writing implement is touching or not touching based on clues about the environment, and determining a best estimate probability based on the stochastic model to determine the likelihood whether the writing implement is touching; and the clues about the environment include shadows of the writing implement.