Video projection is in widespread use for multimedia presentations in classrooms and in conferences. Unfortunately

the usual human-computer interaction (HCI) with keyboard and mouse confines the speaker to the computer devices. In this paper

we present a system for remote HCI using a laser pointer. In addition to the projection equipments

the system only requires a video camera and a video capture card. We use the video camera to capture the projection plane

detect the laser point (that is

the region induced by the laser pointer) in the captured frames. We then track and recognize the trajectory of the laser point and translate it into messages sent to the computer system. Compared with the previous work in this area

we develop some novel ideas in the system: first

a training process is introduced to improve the system adaptability; second

multiple cues such as color appearance

motion

and shape

are integrated in laser point detection to improve the system robustness. The experiments demonstrate the usability (robustness) and adaptability of our system.