Augmented reality

About: Augmented reality is a research topic. Over the lifetime, 36039 publications have been published within this topic receiving 479617 citations. The topic is also known as: AR.

Vision-based tracking with dynamic structured light for video see-through augmented reality

Abstract: Tracking has proven a difficult problem to solve accurately without limiting the user or the application Vision-based systems have shown promise, but are limited by occlusion of the landmarks We introduce a new approach to vision-based tracking using structured light to generate landmarks The novel aspect of this approach is the system need not know the 3D locations of landmarks This implies that motion within the field of view of the camera does not disturb tracking as long as landmarks are reflected off any surface into the camera This dissertation specifies an algorithm which tracks a camera using structured light A simulator demonstrates excellent performance on user motion data from an application currently limited by inaccurate tracking Further analysis reveals directions for implementation of the system, theoretical limitations, and potential extensions to the algorithm The term augmented reality (AR) has been given to applications that merge computer graphics with images of the user's surroundings AR could give a doctor “X-ray vision” with which to examine the patient before or during surgery At this point in time, AR systems have not been used in place of the traditional methods of performing medical or other tasks One important problem that limits acceptance of AR systems is lack of precise registration—alignment—between real and synthetic objects There are many components of an AR system that contribute to registration One of the most important is the tracking system The tracking data must be accurate, so that the real and synthetic objects are aligned properly Our work in augmented reality focuses on medical applications These require precise alignment of medical imagery with the physician's view of the patient Although many technologies have been applied—mechanical, magnetic, optical, et al—we have yet to find a system sufficiently accurate and robust to provide correct and reliable registration We believe the system specified here contributes to tracking in AR applications in two key ways: it takes advantage of equipment already used for AR, and it has the potential to provide sufficient registration for demanding AR applications without imposing the limitations of current vision-based tracking systems

Massive simultaneous remote digital presence world

Abstract: Various methods and apparatus are described herein for enabling one or more users to interface with virtual or augmented reality environments. An example system includes a computing network having computer servers interconnected through high bandwidth interfaces to gateways for processing data and/or for enabling communication of data between the servers and one or more local user interface devices. The servers include memory, processing circuitry, and software for designing and/or controlling virtual worlds, as well as for storing and processing user data and data provided by other components of the system. One or more virtual worlds may be presented to a user through a user device for the user to experience and interact. A large number of users may each use a device to simultaneously interface with one or more digital worlds by using the device to observe and interact with each other and with objects produced within the digital worlds.

ShareVR: Enabling Co-Located Experiences for Virtual Reality between HMD and Non-HMD Users

Abstract: Virtual reality (VR) head-mounted displays (HMD) allow for a highly immersive experience and are currently becoming part of the living room entertainment. Current VR systems focus mainly on increasing the immersion and enjoyment for the user wearing the HMD (HMD user), resulting in all the bystanders (Non-HMD users) being excluded from the experience. We propose ShareVR, a proof-of-concept prototype using floor projection and mobile displays in combination with positional tracking to visualize the virtual world for the Non-HMD user, enabling them to interact with the HMD user and become part of the VR experience. We designed and implemented ShareVR based on the insights of an initial online survey (n=48) with early adopters of VR HMDs. We ran a user study (n=16) comparing ShareVRto a baseline condition showing how the interaction using ShareVR led to an increase of enjoyment, presence and social interaction. In a last step we implemented several experiences for ShareVR, exploring its design space and giving insights for designers of co-located asymmetric VR experiences.

A real-time tracker for markerless augmented reality

Abstract: Augmented reality has now progressed to the point where real-time applications are required and being considered. At the same time it is important that synthetic elements are rendered and aligned in the scene in an accurate and visually acceptable way. In order to address these issues a real-time, robust and efficient 3D model-based tracking algorithm is proposed for a 'video see through' monocular vision system. The tracking of objects in the scene amounts to calculating the pose between the camera and the objects. Virtual objects can then be projected into the scene using the pose. Here, non-linear pose computation is formulated by means of a virtual visual servoing approach. In this context, the derivation of point-to-curve interaction matrices is given for different features including lines, circles, cylinders and spheres. A local moving edge tracker is used in order to provide real-time tracking of points normal to the object contours. A method is proposed for combining local position uncertainty and global pose uncertainty in an efficient and accurate way by propagating uncertainty. Robustness is obtained by integrating an M-estimator into the visual control law via an iteratively re-weighted least squares implementation. The method presented in this paper has been validated on several complex image sequences including outdoor environments. Results show the method to be robust to occlusion, changes in illumination and mistracking.

Augmented reality in neurosurgery: a systematic review

Abstract: Neuronavigation has become an essential neurosurgical tool in pursuing minimal invasiveness and maximal safety, even though it has several technical limitations. Augmented reality (AR) neuronavigation is a significant advance, providing a real-time updated 3D virtual model of anatomical details, overlaid on the real surgical field. Currently, only a few AR systems have been tested in a clinical setting. The aim is to review such devices. We performed a PubMed search of reports restricted to human studies of in vivo applications of AR in any neurosurgical procedure using the search terms "Augmented reality" and "Neurosurgery." Eligibility assessment was performed independently by two reviewers in an unblinded standardized manner. The systems were qualitatively evaluated on the basis of the following: neurosurgical subspecialty of application, pathology of treated lesions and lesion locations, real data source, virtual data source, tracking modality, registration technique, visualization processing, display type, and perception location. Eighteen studies were included during the period 1996 to September 30, 2015. The AR systems were grouped by the real data source: microscope (8), hand- or head-held cameras (4), direct patient view (2), endoscope (1), and X-ray fluoroscopy (1) head-mounted display (1). A total of 195 lesions were treated: 75 (38.46 %) were neoplastic, 77 (39.48 %) neurovascular, and 1 (0.51 %) hydrocephalus, and 42 (21.53 %) were undetermined. Current literature confirms that AR is a reliable and versatile tool when performing minimally invasive approaches in a wide range of neurosurgical diseases, although prospective randomized studies are not yet available and technical improvements are needed.