Designing and

implementing a method for

locating and presenting a

Laser pointer spot

Eran Korkidi

Gil-Ad Ben-Or

IntroductionIntroductionThe 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 projectThe 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 solutionOur 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 solutionOur solution

AlgorithmAlgorithm

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 resultsExperiments and resultsFirst 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 solutionImproving 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 resultsExperiments and results

Experiments and resultsExperiments and results

IR experiments:

The following

picture introduce

our interface and

was taken by an

IR camera

Improving the solutionImproving the solution

Recommended Further work 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 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.