Detection of multiple points of contact on an imaging touch-screen

Touch-screens have emerged as a very popular technology. Touch-screens pervade all electronic devices from laptops to mobile-phones to advanced security systems, up to such a point that any device that does not use touch-screens is deemed outdated. Touch-screens can be broadly classified into three types - capacitive, resistive and imaging. The major advantage of imaging touch screens is its low cost as compared to its counterparts and their upgradation also involves minimal changes to hardware. In areas where there is no necessity of slim touch-screens, image processing touch screens are of a great asset. Essentially, imaging touch-screens are capable of the same functionalities, if not more, as their slimmer counterparts. This includes the latest trend in touch-screen technology, “multi-touch”. This paper discusses a novel algorithm to detect multiple points of contact on an imaging touch surface. The algorithm was implemented using Java programming language and a high level of accuracy was achieved in detecting multiple finger tip blobs for various experiments conducted.