Research On Real-time Collaborative Graphics Editing Systems

Real-time collaborative editing systems are a class of Computer-Supported Cooperative Work (CSCW) systems. In these systems,users can view and edit the same document from geographically distributed sites connected by Web. They have many applications such as textile pattern design,electronic conference and collaborative documentation edit in order to shortening the time,reducing the cost,and improving the quality.There are two categories of collaborative editing systems:text and graphics (including object-based and bitmap-based). Collaborative text editing systems have been widely researched and well-understood,object-based collaborative graphics editing systems are under researching,and bitmap-based collaborative graphics editing systems have not yet been touched.This dissertation carries out several further researches in collaborative editing area,which is based on the newest research deployed in the world. The content are as follows:1. A new multi-version based consistency maintenance algorithm for object-based collaborative graphics editing systems. This algorithm improves the existing multi-version based consistency maintenance algorithm,and the systems' runtime efficiency is enhanced.2. A new semantic preservation model for objected-based collaborative graphics editing systems. Existing researches on this type of systems are focus mainly on syntactic preservation (i.e. consistency maintenance). In this paper,the concept of semantic preservation is proposed and the corresponding model is constructed to enhance the efficiency of collaborative work.3. Consistency preservation and Undo in bitmap-based collaborative graphics editing. Researches on bitmap-based collaborative graphics editing systems have been ceased since 1994. This research resolved the consistency preservation and Undo issues in these systems. The space cost is greatly reduced while only a little time cost is added.This research first achieves a real bitmap-based collaborative graphics editing system in the world,and a paper was published by ACM Conference on CSCW 2002. This paper is the first paper ever accepted by main conferences in CSCW area. Through researching on collaborative graphics editing systems and constructing new generation Internet-based collaborative graphics editing prototype system,a genuine collaborative graphics editing system will be constructed in the near future.