面向多投影显示墙的画面校正与三维交互技术研究

【作者】 王修晖；

【导师】 鲍虎军； 华炜；

【作者基本信息】 浙江大学 ， 计算机科学与技术， 2007， 博士

【摘要】 随着半导体技术和图像处理软硬件技术的不断发展，单台PC机的计算能力和单片图形加速卡的三角形处理能力都有了极大的提高。然而，这些远不能满足交互式虚拟现实系统、数字化商业展出、科学可视化等领域对绘制速度、真实感和显示分辨率等方面的实际需求。基于PC集群的并行绘制系统整合了多台PC机的计算和绘制能力，可以完成单台PC机无法实现的大规模复杂场景的实时真实感绘制，并提供高分辨率、高亮度的显示画面。由于其可伸缩的绘制性能和高分辨率的显示输出，基于PC集群的并行绘制系统成为目前实现高性能、低成本大型绘制平台的首选解决方案。 为了将并行绘制系统生成的高质量图像完整地显示出来，图形显示设备同样需要具有高分辨率、高亮度等特性，因此，单台显示器或投影仪的分辨率和亮度有限性成为实现基于PC集群并行绘制系统的主要瓶颈之一。综合考虑系统性能和构造成本等多种因素，利用计算机图形学和图像处理技术将多台投影仪拼接起来实现多投影显示墙系统成为一个跨学科的研究热点。另一方面，由于通过多台PC机的网络链接实现的并行绘制系统具有节点分布离散、较大通讯延迟和交互空间广阔等特点，传统的单机交互协议和交互方式难以直接进行移植和复用。为了满足在基于PC集群的并行绘制环境下进行三维交互时保持不同绘制节点之间场景状态时空一致性和提高交互方式友好性的需要，交互协议和人机交互方式的研究成为实现交互式并行绘制系统的首要问题之一。 本文深入研究了多投影显示墙画面校正中存在的主要问题和基于PC集群并行绘制环境下的三维交互技术，主要贡献如下： 1．结合一种新的条形校正图案，通过综合考虑识别的鲁棒性和准确性，设计了相应的特征线拟合和特征点检测算法，实现了针对平面幕多投影显示墙的亚像素级几何校正；然后通过曲面逼近算法，将该方案推广到环幕多投影显示墙的几何校正中。 2．根据投影仪工作原理，分析了多投影显示墙环境下影响大屏幕显示效果的各种因素，提出了一种投影仪广义颜色模型，并借助于有理函数逼近的更多还原

【Abstract】 With the rapid development of semiconductor techniques and graphic hardware, the computing power and triangle processing capacity of single PC and graphics accelerator card have been improved greatly. However, those cannot keep up with the increasing requirement of rendering speed, realistic effect and display resolution in applications such as interactive virtual reality systems, digital business exhibit, scientific visualization, etc. PC-cluster based parallel rendering system, which integrates computing power of multiple PC, can realize real-time realistic rendering of large-scale complex scenes, and provide high resolution, high brightness output images. For its extensible rendering performance and high-resolution output, PC-cluster based parallel rendering system becomes a preferred solution to build large rendering platform with high performance and low cost.To perfectly display the output images of parallel rendering system, the limited resolution and brightness of a single display or projector becomes one of the main bottlenecks. Comprehensive considering the performance and cost, fitting several projectors together to build display walls and using computer graphics and image processing techniques to calibration their screen becomes a hot research topic. On the other hand, because parallel rendering systems usually have characters of distribution discreteness, communication delay and wider interaction space, they cannot directly use traditional interaction protocols and modes for stand-alone system. In order to assure the space-time consistence and improve the friendliness while interacting under PC-cluster based parallel rendering system, problems on interaction protocols and information acquisition must be settled firstly.This dissertation is devoted to the researches on screen calibration with multi-projector tiled display wall, and key interaction techniques under更多还原