基于移动增强现实的智慧城市导览

Smart City Guide Using Mobile Augmented Reality

提出一种采用移动增强现实技术实现智慧城市导览的方法,满足用户个性化、多尺度、按需推送的智能导览需求,呈现用户虚实融合的周边环境.移动终端计算性能以及资源存储能力有限,但集成多种传感器,方便携带,易于显示.利用服务器实现基于词汇树的海量场景识别定位系统.依据地理位置信息动态划分分区缩减了场景检索范围,基于二进制鲁棒尺度不变特征(binary robust invariant scalable keypoints,BRISK)进行层级式聚类提高了识别算法的实时性.移动终端利用服务器返回的识别结果进行BRISK特征与光流算法结合的混合特征跟踪注册方法,并通过点集映射消除特征点漂移,利用前后帧信息以及关键帧信息减少跟踪抖动.UKbench标准图像库以及真实环境下的实验结果表明,虚实融合的智能导览效果良好.该原型系统已成功应用于上海电信体验馆等展馆智能导览系统.

A new technique for smart city guide using mobile augmented reality is proposed, which satisfies the personalized, multi-scale, comprehensive needs of users and presents active interface with virtual-real fusion. Mobile side is limited by computing power and resource storage capacity. However, mobile devices usually integrate multiple inertial sensors, which are portable and easy to display. Server side is used for city-scale location recognition based on vocabulary tree method. Dynamic partition method with GPS information reduces the range of image retrieval. Hierarchical k- means clustering on BRISK feature with binary descriptors improves the real-time performance of vocabulary tree. Hybrid features based on BRISK and optical flow are executed in parallel for real- time and robust tracking. Regular re-initialization with BRISK feature is used for reducing errors generated by optical flow. Matching point sets mapping is applied for eliminating drift of feature points during initialization of BRISK feature. Sequence frames and keyframe information are used for reducing jitter with pose estimation. Experimental results on UKbench and real environment demonstrate the advantage of virtual-real fusion for city scale smart guide. Users can easily interact with surrounding real environment. The prototype system has been successfully applied to smart guide system of Shanghai Telecom Experience Venue and other such guide systems.