Research Of Optical-touch Processing Algorithm In Real Time

Optical-touch technology has many advantages with respect to traditional touch system,such as the capacitive touch technology and resistive touch technology. Firstly, the screen of optical-touch system is not dependent foreground glass or other transparent materials as transfer medium which will reduce the light transmittance. Secondly, optical-touch system does not require physical access to the touch screen, prolonged stress exposure may cause screen burn-in problems, optical-touch system can detect the position of the target of contact by blocking the beam in the interaction region; Further, the most important point, Traditional touch-screen technology needs conduction medium, so the screen on the production process requires high cost and difficult to expand in the large size of the screen, with the rapid development of optical sensors, optical touch technology is suitable to be applied on the large screen. The fast processing algorithm was designed for the emerging optical touch system and the optical-touch algorithm has been validated optical touch platform which has two optical cameras.The main contents of this paper are as follows:(1) Researching Implementation process of optical-touch platform works which has two optical cameras. The optical-touch platform detects fingers movement in the interactive area. Each camera received a one-dimensional image, analysis of the contact information on the one-dimensional image, the contact coordinates are mapped to the two-dimensional image. According to the characteristics of optical-touch system and digital image of theory, this subject has designed an optical-touch algorithm and analysis of the logical relationship between the various sub-algorithms.(2) Contact detection algorithm, localization algorithm and tracking algorithm is the basis of the entire optical touch algorithm. This paper presents a gradient-based detection of the contact detection algorithm to achieve detection of multi-points in one image; Then using the calibration results, presented an angle positioning method of algorithm to achieve fast positioning contacts which is based on the results of the calibration; Finally, the contact tracing algorithm attributed to matching problem in graph theory optimal bipartite graph, associated with the nearest neighbor algorithm to achieve a stable tracking contacts.(3) Researching the algorithm of described gesture and the algorithm of gesture matching, the gesture commands decomposed into many atomic gestures, Atomic gesture is coded by using the Freeman chain code, after the code is improved by correction algorithm and simplified algorithm, distinguished gesture commands by judging the difference atomic gestures of number, spatial relations, time, kind of relationship. This article discusses two atomic gestures matching algorithm and selected the LCS-based matching algorithm to match atomic gestures by comparison, it can be a true reflection of the similarity matching chain-code.After the comprehensive testing, it is proved that the optical-touch method can achieve interactive features can achieve human-computer interaction. Optical-touch algorithm can handle 240 images in a second(optical touch platforms effective interaction area the size of 50 cm * 30cm), it is able to identify 12 kinds of complex gestures, finished entering commands via touch gestures, simulated six mouse button functions, the algorithm of real-time has been proved.