建立单摄像机虚拟鼠标的数学模型,提出一种虚拟鼠标的现场标定方法。以二维实体靶标为中介,利用计算机屏幕生成的虚拟靶标,确定摄像机坐标系到屏幕坐标系的变换,建立空间三维控制点图像坐标到鼠标指针的映射,实现了单摄像机虚拟鼠标的现场标定。提出的方法无需高成本的辅助设备,现场操作简单。在30 cm作用距离内采用640 pixel×480 pixel图像中50个特征点,当图像噪声方差达到1 pixel时,试验中控制点映射为屏幕坐标的均方根(RMS)误差小于3 pixel。该方法应用于研发的虚拟鼠标演示程序,表明切实可行,适用于虚拟鼻尖鼠标的现场标定。

The mathematical model of a single-camera virtual computer mouse sensor is established and a field calibration approach to the single-camera virtual mouse is proposed. The mapping from the camera coordinates in working status to the screen coordinates can be calibrated through one media planar target in the camera′s field of view and one virtual target on the screen. Calibrating the single-camera virtual mouse is completed by efficiently establishing an available correspondence between the three-dimensional control point in space and the point of the mouse in the operating system. The proposed approach has an easy operation,and demands no extra costly tools. In the work range of 30 cm and with 50 features from image in 640 pixel×480 pixel,the RMS errors of the control point coordinates in the screen under test are within 3 pixels when the image noise variance reaches 1 pixel. The demo program shows the proposed approach is practicable and is applicable to field calibration for virtual mouse based on the tip of the user′s nose.