Computer-based presentations are facilitated by a projector connected to a computer to project a computer screen image onto a projection surface, such as a projection screen surface or a wall surface. The projected computer screen image can be the viewable output image of the computer, which is commonly displayed on a computer monitor. Thus, a computer-based presentation may involve displaying what would typically be displayed on a computer monitor. However, the projected computer screen image may be an electronic image that is different than the image displayed on the computer monitor.
In order to point to a specific item in a projected computer screen image during a computer-based presentation, a presenter may use any laser pointer to point to that specific item in the projected computer screen image. The laser pointer is used to create a laser spot on the projection surface, which allows viewers to know what item to which the presenter is pointing. However, a laser pointer typically cannot be used to control the computer-based presentation. Rather, the computer keyboard and/or the computer mouse are usually used to control the computer-based presentation, which anchors the presenter to the computer and limits the mobility of the presenter.
Recently, laser pointer tracking systems have been developed to optically track the laser spot on the projection surface to control the cursor of the computer that is being used to provide the projected computer screen image. The laser pointer used in some of these systems may include buttons or other controls, which emulate computer mouse buttons. Thus, using a laser pointer tracking system, the presenter can freely move about without having to return to the computer to control the computer-based presentation.
A concern with some conventional laser pointer tracking systems is that the systems must be manually calibrated before use. In particular, the position of the projected computer screen image on the projection surface must be manually entered into the system so that the system can determine the location of a laser spot relative to the original computer screen image to move the cursor to that location. Typically, this involves pointing the laser pointer to each corner of the projected computer screen image on the projection surface during a calibration process, which can be annoying to some users.
Thus, there is a need for a laser pointer tracking system, which can automatically perform a calibration process.