Research On Key Technologies Of Augmented Expression For Paper Map

The augmented expression for paper maps refers to the realization of a new type of geographic information expression mechanism by combining augmented reality technology to expand the expression content of paper maps and enhance their interactive functions.With the high popularity of mobile terminals such as smartphones,the combination of mobile augmented reality and paper maps is one of the best ways to realize the diverse expression of paper maps.A link between the paper maps and the virtual information can be established through the camera of the mobile terminals,and then the virtual information and the paper maps can be seamlessly connected.The users can interact with the paper maps through the mobile terminal to obtain the geographic information service of interest.The aim of this paper is to implement the augmented expression of paper maps by mobile augmented reality technology,and the key technology of mobile augmented reality,the natural feature based tracking and registration algorithm,is deeply studied.And the main contents of this paper are as follows:1.Explaining the meaning of the augmented expression for paper maps,sorting out the status of the augmented expression for paper maps and tracking registration technology based on natural features,and then summarizing and analyzing the existing deficiencies.2.Designing a technological process of the augmented expression for paper maps through the analysis of the map expression model and the mobile augmented reality technology and its characteristics.3.Selecting ORB algorithm as the basis of the image matching algorithm through the principle introduction and performance comparison analysis of image matching algorithm based on natural features commonly used in tracking registration.4.Proposing a method of using homography matrix estimation to improve ORB's low accuracy by removing outliers.And proposing a homography matrix cyclic correction method to improve the accuracy of the homography matrix and then meet the accuracy requirements of tracking and registration.5.Combining homography matrix cyclic correction method and L-K optical flow method to realize image feature tracking for solving the limitations of the mobile terminal's hardware capabilities,thereby improving the tracking registration efficiency of mobile terminals.6.Developing a paper map augmented expression prototype system.The development of a paper map enhanced expression prototype system was realized.The prototype system developed in this paper is based on the ORB algorithm and combines the homography matrix cyclic correction and L-K optical flow method.It can realize tracking registration in real time,realize enhanced expression of paper maps,and improve the user's interactive experience.