Augmented Reality-based Tour Guidance in Streets by Use of Smart Phones
|關鍵字:||擴增實境;旅遊導覽;行動裝置;消失點;使用者定位;augmented reality;tour guidance;mobile device;vanishing points;user localization|
When people go to an outdoor tour area, they might get lost or have no idea about how to reach desired locations or buildings. In this study, an augmented reality (AR)-based tour guidance system for use in outdoor tour areas by computer vision techniques is proposed. With the proposed system, a tour guidance map can be constructed in advance to provide tour guidance information to a tourist. The system provides two main functions: tour guidance and building-information introduction, both based on AR techniques. The system can guide a touring user to the location of a pre-selected building and augment the information of the building on the screen of a smart-phone held by the user. To implement a system with the above-mentioned capabilities, at first an environment map is generated in a learning phase, which includes the top-view map of a selected tour path area and the information about the along-path buildings. In addition, the images of the buildings taken by the smart-phone camera and the corresponding building locations along the whole tour path are also learned. All the learned data are saved into a database for use in the navigation phase. Next, a method for user localization is proposed for use by the system. The method is based on image recognition using speeded up robust features (SURFs). At first, the user takes an image of a nearby building. Secondly, recognition of the building image is conducted against the pre-constructed image database by an SURF matching algorithm. Finally, user localization is accomplished by the system to obtain the user’s position and orientation parameters according to the perspective relationship between the image taken by the user as well as the matching result. Furthermore, a method for AR-based guidance and building-information introduction is proposed. Based on the user’s position and orientation parameters, the system can plan a shortest path from the user’s location to a pre-selected destination by use of the Dijkstra algorithm. Accordingly, an AR-based arrow is created and augmented on the acquired along-path building image on the smart-phone screen to guide the user where to go. Also augmented on the smart-phone screen is the information of the building name as well as the distance between the user and the building appearing in the acquired image which is computed according to the user localization result. Good experimental results are also presented to show the feasibility of the proposed methods and system for real applications.