Abstract: To solve the problem of the picture distorted that is caused when the picture is projected to semispheric screen, this paper presents a method about semispheric screen geometry correction and camera calibration. The method finds out the corresponding relations and computational method between 3D semispheric space and 2D projector space, builds the mathematical model of semisperic screen projective space. It obtains the predeformation grid by back projecting the ideal grid demarcated on the semispheric screen to projector space, makes the geometry transformation between predeformation grid and prespective grid by Singular Value Decomposition(SVD), calibrates the camera by control points fitting. A multi-touch system platform based on semispheric screen is implemented, experimental result shows that the method achieves expected object.

Key words: spheric screen, geometry correction, camera calibration, Singular Value Decomposition(SVD), control points fitting

摘要： 为解决半球幕投影图像画面图形畸变的问题，提出一种半球幕几何校正和相机标定的方法。该方法通过3D半球幕空间与2D投影机空间的对应关系，建立投影空间数学模型。将半球幕上标定的理想球形网格反投影到投影机空间获取预变形网格。通过奇异值分解法进行预变形网格与平面透视网格间的几何关系变换，通过控制点拟合法进行相机标定，实现基于半球幕的多点触控系统。实验结果表明该方法达到预期目标。

关键词: 球形幕, 几何校正, 相机标定, 奇异值分解, 控制点拟合

CLC Number: 

• TP391