Research On Three Dimensional Objects Registration And Localization Technology Based On Wire-frame Model

Augmented Reality is a new multidisciplinary crossing research field, which can enhance or expand person's visual by fusing the real world scene and graphics and text annotation virtual information generated by computer. The key technology of augmented reality system is registration and localization, which can detect the camera position and direction of the line of sight in real-time. According to this information to determine the mapping location of virtual information to be added. Let virtual information display in the correct position in real-time. The performance of registration and localization technology will produce a great impact on the stability and robustness of augmented reality system.According to the registered objects, registration and localization technology can be divided into based on two dimensional objects and based on three dimensional objects. This thesis mainly studies registration and localization technology based on three dimensional objects.,And completed an augmented reality system based wire frame model on smart-phone.The main work of this thesis is listed as following:1. Research on the Augmented Reality technology background, application field, domestic and foreign development present situation of registration and localization technology of two dimensional and three dimensional objects as well as the realization method. Pointed out the difficulties of three dimensional registration and localization technology. Briefly analyzed based on the model and parallel reconstruction three dimensional registration method. And pointed out that the focus on the research is the three dimensional objects registration and localization technology based on wire-frame.2. Described the implementation of wire-frame detection about this system in detail.Firstly built system frame and described the wire-frame model. Secondly described the method of wire-frame detection is divided into two kinds. One is based on the edge detection. Analyzed the performance of several kinds of classical edge detection algorithm.Another method is based on the point and line. This method is to remove noise according to the topology of point and line within wire-frame model and constraint conditions to get accurate wire-frame. Verified the effectiveness of the proposed method. Finally rendered,projected and established different objects' three dimensional models. Including use Opengl ES rendering and three dimensional modeling software rendering of different kinds of three dimensional models. Transformed each of the three dimensional model from different scales and different angles and got fifty-four three dimensional models.3. Described the implementation of three dimensional object's registration and tracking of the system. Firstly located three dimensional object using hausdorff distance matching method according to the wire-frame and projection of three dimensional model, and find the best matches three dimensional model with current stance of wire-frame. Secondly analyzed the performance of different search algorithms. The experiment proved that using Depth-First-Search combined with Breadth-First-Search method to track three dimensional object can.effectively improved the robustness and real-time performance of the system relative to the violent search algorithm. Finally with solve Pn P algorithm to get the camera first pose, after which with RPP algorithm to iterate and find pose that has the minimum error to fuse virtual information and real scene.4. This thesis completed a set of three dimensional object's registration and localization prototype system based on mobile terminal. Developed software under Android platform using the jni(Java Native Interface) approach. Verified the feasibility and effectiveness of the system through the experiments of different three dimensional objects.