Construction of a lighting model of the real world is one of the critical aims in an augmented reality (AR) system. The theory of lighting modeling used in computer graphics(CG) is applied in this study. The position...Construction of a lighting model of the real world is one of the critical aims in an augmented reality (AR) system. The theory of lighting modeling used in computer graphics(CG) is applied in this study. The position of the real light-source is first conjectured from light and shade of the registration image element by element using a ray tracking algorithm. Then the virtual light-source and virtual fiducial are constructed in the CG environment, in which, the Phong model is used to draw the light effect. By comparing the CG scene with the real image, one can modify the parameters of the lighting model over and over again, until the lighting effect of the CG scene is close enough to that of the real image. It is proved that this method works well in the indoor AR system. The method can be used feasibly in most applications with some improvements.展开更多
This paper proposes a novel registration method for augmented reality(AR) systems based on Oriented FAST and RotatedBRIEF(ORB) and Fast Retina Keypoint(FREAK) natural features. In the proposed ORBFREAK method, feature...This paper proposes a novel registration method for augmented reality(AR) systems based on Oriented FAST and RotatedBRIEF(ORB) and Fast Retina Keypoint(FREAK) natural features. In the proposed ORBFREAK method, feature extraction is implemented based on the combination of ORB and FREAK, and the feature points are matched using Hamming distance. To get good matching points, cross-checks and least median squares are used to perform outlier filtration, and camera pose is estimated using the matched points. Finally, AR is rendered.Experiments show that the proposed method improves the speed of registration to be in real time; the proposed method can accurately register the target object under the circumstances of partial occlusion of the object; and it also can overcome the effects of rotation, scale change, ambient light and distance.展开更多
This paper proposes an outdoor guide system using vision-based augmented reality(AR) on mobile devices.Augmented reality provides a virtual-real fusion display interface for outdoor guide.Vision-based methods are more...This paper proposes an outdoor guide system using vision-based augmented reality(AR) on mobile devices.Augmented reality provides a virtual-real fusion display interface for outdoor guide.Vision-based methods are more accurate than GPS or other hardware-based methods.However,vision-based methods require more resources and relatively strong computing power of mobile devices.A C/S framework for vision based augmented reality system is introduced in this paper.In a server,a vocabulary tree is used for location recognition.In a mobile device,BRISK feature is combined with optical flow methods to track the offline keyframe.The system is tested on UKbench datasets and in real environment.Experimental results show that the proposed vision-based augmented reality system works well and yields relatively high recognition rate and that the mobile device achieves realtime recognition performance.展开更多
文摘Construction of a lighting model of the real world is one of the critical aims in an augmented reality (AR) system. The theory of lighting modeling used in computer graphics(CG) is applied in this study. The position of the real light-source is first conjectured from light and shade of the registration image element by element using a ray tracking algorithm. Then the virtual light-source and virtual fiducial are constructed in the CG environment, in which, the Phong model is used to draw the light effect. By comparing the CG scene with the real image, one can modify the parameters of the lighting model over and over again, until the lighting effect of the CG scene is close enough to that of the real image. It is proved that this method works well in the indoor AR system. The method can be used feasibly in most applications with some improvements.
基金supported by Tianjin Sci-tech Planning Projects (14RCGFGX00846)Natural Science Foundation of Hebei Province (F2015202239)+1 种基金Tianjin Sci-tech Planning Projects (15ZCZDNC00130)Science and Technology Research Project of Hebei Province (Z2015044)
文摘This paper proposes a novel registration method for augmented reality(AR) systems based on Oriented FAST and RotatedBRIEF(ORB) and Fast Retina Keypoint(FREAK) natural features. In the proposed ORBFREAK method, feature extraction is implemented based on the combination of ORB and FREAK, and the feature points are matched using Hamming distance. To get good matching points, cross-checks and least median squares are used to perform outlier filtration, and camera pose is estimated using the matched points. Finally, AR is rendered.Experiments show that the proposed method improves the speed of registration to be in real time; the proposed method can accurately register the target object under the circumstances of partial occlusion of the object; and it also can overcome the effects of rotation, scale change, ambient light and distance.
基金Supported by the National Science and Technology Major Project(No.2012ZX03002004)the National High Technology Research and Development Programme of China(No.2013AA013802)
文摘This paper proposes an outdoor guide system using vision-based augmented reality(AR) on mobile devices.Augmented reality provides a virtual-real fusion display interface for outdoor guide.Vision-based methods are more accurate than GPS or other hardware-based methods.However,vision-based methods require more resources and relatively strong computing power of mobile devices.A C/S framework for vision based augmented reality system is introduced in this paper.In a server,a vocabulary tree is used for location recognition.In a mobile device,BRISK feature is combined with optical flow methods to track the offline keyframe.The system is tested on UKbench datasets and in real environment.Experimental results show that the proposed vision-based augmented reality system works well and yields relatively high recognition rate and that the mobile device achieves realtime recognition performance.
