Geographic Stereo Video Web Services: Framework Design and Interface Development

Abstract

The traditional multimedia map,which combines map and multimedia elements,represents the geographic world more visually.With the rapid advance of the multimedia and position technology,the new-style geo-tagged media,such as geographic video,panoramic picture and measurable image,have been introduced in GIS applications.This paper aims to introduce the stereo video to GIS.Geographic stereo video includes both spatial and temporal geographic characteristics acquired through ground-based or non-ground-based cameras.It is the stereo video that extends the elements of interior and exterior orientation for video frame.Therefore,it supports the video retrieval and image measurement based on the spatial information,And it has been a new way for geographic representation.With the wide application of web service technology,geographic stereo video web service will further expand the video GIS application.To fully utilize the geographic stereo video resource in web environment,this paper aims to design a framework of geographic stereo video web services and to develop the related RESTful web interfaces.Based on the discussion of functional requirements such as visualization,querying and measurement,a web service framework composed of data layer,service layer and presentation layer for geographic stereo videos is introduced.All functions are packaged as a service in this framework and its communication are based on a unified interface,standard protocol and universal data format.The video URI resources,its representation format and related operation interfaces are defined carefully as the RESTful web services.The client-server interaction mechanisms for video querying,video displaying and image measurement are outlined in details.All the geographic stereo video web services are implemented on the basis of Windows Communication Foundation(WCF) and ArcGIS Server technologies.Based on the geographic stereo video service and browser-side AJAX(Asynchronous JavaScript and XML) programming,a prototype system of geographic stereo video web service for Henan University(Jinming campus) was developed.The prototype application shows that the service framework and system design introduced in this paper is feasible and adequate for video GIS application development.It is of reference value for web service standardization of new-style geo-tagged media.