Abstract: Non-planar projection has been widely applied in virtual reality, digital entertainment and exhibitions for its flexible layout and immersive display effects. Compared with planar projection, non-planar projection is more difficult to achieve since the problem of projector calibration and image distortion correction. The current projection calibration algorithm can be divided into two categories, using 3D reconstruction or not. Methods using 3D reconstruction are time-consuming and require costly equipments. Methods do not use 3D reconstruction may require manual operation and has poor adaptability in view-independent applications. This paper particularly studies the property of cylindrical screen and presents a novel method for calibrating multi-projector automatically in non-planar environment without 3D reconstruction. This method can correct the error caused by manufacturing and arranging of the screen, and it also can be used in surface which can be parameterized, like sphere, ellipsoid, paraboloid, etc.

Key words: multi-projector, geometric registration, non-planar display

摘要： 非平面投影以其高度的沉浸感、多样的表现形式和灵活的场景布局，近年来越来越多地应用在虚拟现实、数字娱乐、展览展示等领域。非平面投影与平面投影相比，由于涉及到投影机位姿标定以及失真图像校正等问题，实现难度较高。目前的投影校正方法虽然可以通过重建或者非重建方法实现非平面屏幕投影的几何校正，但是它们多少都存在成本高昂，步骤复杂，需要人工干预，适用面窄等问题。针对非平面屏幕中最常使用的柱幕面型，提出一种非重建的多投影机投影几何校正方法，此方法可自动实现柱幕环境的几何投影校正，并且可对柱幕在加工中引入的倾斜、表面起伏等外形偏差予以修正，实现了复杂柱幕环境下多投影机高精度、短时间投影几何校正。提出的方法不仅适用于柱幕，还可扩展应用于其他可参数化描述的面型，如球面、双曲面、抛物面等面型的投影环境，具有广泛的适用性。

关键词: 多投影机, 几何校正, 非平面显示