Study On Construction And Optimization Of Context-aware Based Mobile Augmented Reality Browser

In recent years, with the rapid development of mobile Internet and mobile intelligent terminals, more and more people use mobile applications to deal with everyday affairs. Because of their quick and convenient services to people, location-based applications become one of the most popular mobile applications. Because Augmented Reality browser is able to superimpose virtual data onto the real environment, it changes the way of human-computer interaction(HCI) from keyboard and mouse actions on two-dimensional screen to somatosensory control in three-dimensional space accordingly and quickly receives people’s recognition after its release.The latest research shows that despite user’s attention to augment reality services, its usage frequency is low and the usage time is short. In reality, there is a contradictory phenomenon of high installation rate and low usage rate. The intrinsic reason lies in the ignorance of human factors, which causes the design defect in the design stage of augmented reality browser. To solve this problem, this dissertation conducts a systematic study on the Augmented Reality browser. Based on the theory of Image Processing, Cognitive Science, Design Psychology, Human-computer Interaction Design etc. This dissertation proposes a new type of mobile Augmented Reality browser system, through which the system performance is optimized by employing an iterative design. Research results are called upon to solve the problems caused by human error existing in current mobile Augmented Reality browser, and consequently improve the user experiences of interaction significantly. The main innovations of this research include:(1) This dissertation presents a method of pushing context-aware service based on scene classification to overcome the improper use of Augmented Reality browser’s label caused by the interference with user’s cognitive operations. User’s scene is separated by using the proposed method on the basis of user’s cognitive processes when searching and retrieving points of interest. The function module of three scenes is built by using the framework of four-layer context-aware services respectively. By utilizing large scale scene recognition algorithm based on vocabulary tree in the proposed prototype of Augmented Reality browser, points of interest in the scene can be accurately identified. Real-time registration and pixel-level tracking are achieved by using BRISK feature algorithm. The overall construction of the Augmented Reality system is completed by associating three scenario modules. Experimental results of comparison with the existing popular browsers show that the classification accuracy of the system constructed by using the proposed method is improved by 13% on average, and the user’s average satisfaction with the prediction effect of the system by about 26%.(2) To solve the problem of human errors caused by design deviation in Augmented Reality browser, a novel design flow of information visualization and interaction design is developed. Based on the comparisons between the proposed Augmented Reality browser and the traditional ones, user requirements are extracted at first. Then the abstracted information is visualized as data view and the method of overview and detail is used to lay out the visual elements that make up the view after user requirements are transformed into a task list. Thirdly, by using the coordinate calculation method for label display on the basis of the angle projection, the implementation of visual interface of Augmented Reality browser is achieved. Fourthly, the interactive interface is generated through organizing discrete data view by incremental interactive method. Finally the design errors in the evaluation process are resolved after three iterative designs of prototypes. Task load index method is employed in usability evaluation and experimental results show that the task load index overall score of the proposed system is higher than the other subjects about 10 percents. This also reduces user’s cognitive load for two testing factors of “Temporal demand” and “Frustration Level”.(3) To solve the problem of enhancing user’s perception of the point of interest, a novel interactive mode which is used for virtual reality and augmented reality hybrid mobile navigation is proposed on the basis of mental model theory. A HCI experiment is conducted by combining the Macro Mental Model and Micro Mental Model. The user interface is developed and realized through repeated evaluation and usability testing based on the implentation of user-centered design principles. Then the interactive experience of the proposed system approaches the user’s psychological expectations. Furthermore, through the spontaneous switch between virtual reality and augmented reality environments, users can obtain two distinct interactive experiences. The experimental results demonstrate that the user interface design of this system not only mobilizes the enthusiasm of user interaction, but also improves the usability and efficiency of HCI.(4) In order to overcome the bottlenecks of limited data wireless transmission speed and insufficient mobile phone graphics rendering capacity that lead to the interruption of user interaction experiences, an optimized process that simplifies the complexity of the 3D model of the scene and improves the strategy of resource set configuration and loading is proposed. Firstly, the reverse mapping method of normal map is utilized to simplify the geometric structure of the model. Then the preset of the scene is generated after the whole virtual scene has been created, through which all models are packaged into a set of resources. According to the calling frequency of model by scene, all models in resource set are divided into the common model and the difference model. The difference model is placed on the clouds and common model on smart phones. Finally the resources set is downloaded from both ends and loaded into a new scene asynchronously. Experimental results show that the system memory footprint is reduced by more than half of the phone memory in the resource set loading phase. By using this novel optimized process, the fluency of user interaction experience has also been raised. Furthermore, more than twofold increase of view refresh frame rate improves the display quality of user interface.