题目/Title：一种基于高频率投影仪—摄像头的人机交互系统
                        High-frequency pro-cam based human-computer interaction system

作者/Author：胡云普,麦宋平,谢翔
                        Yunpu Hu,Songping Mai,Xiang Xie

期刊/Journal：计算机应用研究 Application Research of Computers

年份/Issue Date：2017.Mar.

卷（期）及页码/Volume（No.）&pages：Vol.34, No.3, pp. 907-910

摘要/Abstract：
针对桌面投影设备,提出了一种基于单投影仪-单摄像头的人机交互系统架构,可以实现在投影面上的类触摸屏操作.其中,提出了一种基于高速投影中互补阴影的方法,在不影响使用者视觉体验的前提下实现触碰点位置检测与触碰判断.针对低强度差分阴影的提取,提出了基于马尔可夫随机场模型的最优化方法,提高了复杂环境噪声下阴影分割的鲁棒性.针对指尖检测,使用了一种基于最小二乘法的曲率估计方法,提高了触碰定位的准确度.触碰判断方面,提出了一种基于双目约束与几何模型的高精度触碰判断准则.实验证明,本系统达到触碰识别率99.2%, 误识
This paper proposed a novel projector-camera based human-computer interaction system for touch-pad application of tabletop projection. Taking the advantage of differential shadow in high-frequency projection, the system realized the localization and judgment of touch action without influencing users’ visual experience. A Markov Random Field based shadow segmentation method helped to robustly extract the low-intensity shadow under complex environment. To precisely locate fingertip, the algorithm searched along the contour of the shadow and used a least square method to estimate the curvature of the shadow contour. Furthermore, the binocular constraint and geometrical model based touch judging method helped to raise the touch judging precision in the system. The experiment showed that the proposed system performs better than state-of-art works, with touch recognition rate at 99.2%, false alert rate at 0.6% and touch localization accuracy at 1.77pixels. Meanwhile, the system works at 60 fps on a conventional PC, which satisfies the requirement of most of real-time applications.