Designing and implementing a method for locating and presenting a Laser pointer spot Eran Korkidi Gil-Ad Ben-Or

Introduction The project presented here describes an alternative method for controlling a mouse using a laser pointer when showing a presentation.

Locating and presenting the spot of a laser pointer on a projection screen can be useful for many applications, for example: The purpose of the project Enhancing laser pointer appearance on screen. By presenting the laser point via the computer, we can sketch contours on the projection. Replacement Interface for a Wireless Mouse.

Our solution Detecting the red spot of the laser pointer is done by a camera. The camera is directed to the projection screen, and calibrated according to the specifications of the relevant projected area, focus and zoom.

After The camera locates the laser spot on the screen, the program updates the pointer state, taking into consideration the location of the spotted point and presents it via the projector. Our solution

Algorithm Find the brightest area on the screen. Average positions of all bright points on the screen to extract pointer location. Transform the resulting coordinates to screen coordinates. Update pointer position.

Experiments and results First experiments were made with a adjacent frame difference approach. The results show that with the equipment we used, there is a need for another level of filtering.

Improving the solution Problem: Finding a small spot on the screen is problematic due to high rates of noise. Solution: Use an infrared camera and laser pointer let us “see” only the laser pointer and ignore background noise. Experiments and results

We use a 904nm laser and a camera that can detect infrared light to separate visible light from the laser pointer. Experiments and results Improving the solution

Experiments and results IR experiments: The following picture introduce our interface and was taken by an IR camera Improving the solution

Recommended Further work Implementation of kalman filter for contour estimation, thus inhibiting any unwelcome disturbance or noise. Full Interface interaction with the mouse cursor while lecturing with a presentation. Support a wider range of cameras, using less expensive cameras.

Conclusion Our goal in this project was to design a system that locates a laser spot and presents it via projector. The solution described here answer the problem that presented above. Future work is needed to implement better IR system and Additive Kalman Filter.