当今投影仪已经广泛地应用于教学和会议之中，可是，传统的基于键盘和鼠标的人机交互仍然将演讲者限制在计算机设备旁边，从而给演讲者带来了不便．为解决此问题，提出了一种新的基于激光笔的远程人机交互系统．该系统只需要添加一个摄像机和视频采集卡就可以实现远程的人机交互，即在进行交互时，首先用一个摄像机实时拍摄投影屏，然后在得到的图中，检测激光点区域，并且跟踪识别它的轨迹，再将识别的结果作为用户输入，提供给计算机系统．与以往的类似系统相比，该系统的新颖之处有：在使用前即可训练出关于环境和激光点的特征，以用于增强系统的适应性；由于可通过融合多种信息(比如颜色、运动以及形状信息)来检测激光点，因而增强了系统的鲁棒性．实验结果表明，该系统具有较强的可用性(鲁棒性)和适应性．

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.