Bringing Telepresence to Every Desk

In this paper, we work to bring telepresence to every desktop. Unlike commercial systems, personal 3D video conferencing systems must render high-quality videos while remaining financially and computationally viable for the average consumer. To this end, we introduce a capturing and rendering system that only requires 4 consumer-grade RGBD cameras and synthesizes high-quality free-viewpoint videos of users as well as their environments. Experimental results show that our system renders high-quality free-viewpoint videos without using object templates or heavy pre-processing. While not real-time, our system is fast and does not require per-video optimizations. Moreover, our system is robust to complex hand gestures and clothing, and it can generalize to new users. This work provides a strong basis for further optimization, and it will help bring telepresence to every desk in the near future. The code and dataset will be made available on our website https://mcmvmc.github.io/PersonalTelepresence/

A framework for realistic 3D tele-immersion

Meeting, socializing and conversing online with a group of people using teleconferencing systems is still quite differ- ent from the experience of meeting face to face. We are abruptly aware that we are online and that the people we are engaging with are not in close proximity. Analogous to how talking on the telephone does not replicate the experi- ence of talking in person. Several causes for these differences have been identified and we propose inspiring and innova- tive solutions to these hurdles in attempt to provide a more realistic, believable and engaging online conversational expe- rience. We present the distributed and scalable framework REVERIE that provides a balanced mix of these solutions. Applications build on top of the REVERIE framework will be able to provide interactive, immersive, photo-realistic ex- periences to a multitude of users that for them will feel much more similar to having face to face meetings than the expe- rience offered by conventional teleconferencing systems

REAL-TIME CAPTURE AND RENDERING OF PHYSICAL SCENE WITH AN EFFICIENTLY CALIBRATED RGB-D CAMERA NETWORK

From object tracking to 3D reconstruction, RGB-Depth (RGB-D) camera networks play an increasingly important role in many vision and graphics applications. With the recent explosive growth of Augmented Reality (AR) and Virtual Reality (VR) platforms, utilizing camera RGB-D camera networks to capture and render dynamic physical space can enhance immersive experiences for users. To maximize coverage and minimize costs, practical applications often use a small number of RGB-D cameras and sparsely place them around the environment for data capturing. While sparse color camera networks have been studied for decades, the problems of extrinsic calibration of and rendering with sparse RGB-D camera networks are less well understood. Extrinsic calibration is difficult because of inappropriate RGB-D camera models and lack of shared scene features. Due to the significant camera noise and sparse coverage of the scene, the quality of rendering 3D point clouds is much lower compared with synthetic models. Adding virtual objects whose rendering depend on the physical environment such as those with reflective surfaces further complicate the rendering pipeline. In this dissertation, I propose novel solutions to tackle these challenges faced by RGB-D camera systems. First, I propose a novel extrinsic calibration algorithm that can accurately and rapidly calibrate the geometric relationships across an arbitrary number of RGB-D cameras on a network. Second, I propose a novel rendering pipeline that can capture and render, in real-time, dynamic scenes in the presence of arbitrary-shaped reflective virtual objects. Third, I have demonstrated a teleportation application that uses the proposed system to merge two geographically separated 3D captured scenes into the same reconstructed environment. To provide a fast and robust calibration for a sparse RGB-D camera network, first, the correspondences between different camera views are established by using a spherical calibration object. We show that this approach outperforms other techniques based on planar calibration objects. Second, instead of modeling camera extrinsic using rigid transformation that is optimal only for pinhole cameras, different view transformation functions including rigid transformation, polynomial transformation, and manifold regression are systematically tested to determine the most robust mapping that generalizes well to unseen data. Third, the celebrated bundle adjustment procedure is reformulated to minimize the global 3D projection error so as to fine-tune the initial estimates. To achieve a realistic mirror rendering, a robust eye detector is used to identify the viewer\u27s 3D location and render the reflective scene accordingly. The limited field of view obtained from a single camera is overcome by our calibrated RGB-D camera network system that is scalable to capture an arbitrarily large environment. The rendering is accomplished by raytracing light rays from the viewpoint to the scene reflected by the virtual curved surface. To the best of our knowledge, the proposed system is the first to render reflective dynamic scenes from real 3D data in large environments. Our scalable client-server architecture is computationally efficient - the calibration of a camera network system, including data capture, can be done in minutes using only commodity PCs

A low-cost, practical acquisition and rendering pipeline for real-time free-viewpoint video communication

We present a semiautomatic real-time pipeline for capturing and rendering free-viewpoint video using passive stereo matching. The pipeline is simple and achieves agreeable quality in real time on a system of commodity web cameras and a single desktop computer. We suggest an automatic algorithm to compute a constrained search space for an efficient and robust hierarchical stereo reconstruction algorithm. Due to our fast reconstruction times, we can eliminate the need for an expensive global surface reconstruction with a combination of high coverage and aggressive filtering. Finally, we employ a novel color weighting scheme that generates credible new viewpoints without noticeable seams, while keeping the computational complexity low. The simplicity and low cost of the system make it an accessible and more practical alternative for many applications compared to previous methods

A mixed reality telepresence system for collaborative space operation

This paper presents a Mixed Reality system that results from the integration of a telepresence system and an application to improve collaborative space exploration. The system combines free viewpoint video with immersive projection technology to support non-verbal communication, including eye gaze, inter-personal distance and facial expression. Importantly, these can be interpreted together as people move around the simulation, maintaining natural social distance. The application is a simulation of Mars, within which the collaborators must come to agreement over, for example, where the Rover should land and go. The first contribution is the creation of a Mixed Reality system supporting contextualization of non-verbal communication. Tw technological contributions are prototyping a technique to subtract a person from a background that may contain physical objects and/or moving images, and a light weight texturing method for multi-view rendering which provides balance in terms of visual and temporal quality. A practical contribution is the demonstration of pragmatic approaches to sharing space between display systems of distinct levels of immersion. A research tool contribution is a system that allows comparison of conventional authored and video based reconstructed avatars, within an environment that encourages exploration and social interaction. Aspects of system quality, including the communication of facial expression and end-to-end latency are reported

A multi-projector CAVE system with commodity hardware and gesture-based interaction

Spatially-immersive systems such as CAVEs provide users with surrounding worlds by projecting 3D models on multiple screens around the viewer. Compared to alternative immersive systems such as HMDs, CAVE systems are a powerful tool for collaborative inspection of virtual environments due to better use of peripheral vision, less sensitivity to tracking errors, and higher communication possibilities among users. Unfortunately, traditional CAVE setups require sophisticated equipment including stereo-ready projectors and tracking systems with high acquisition and maintenance costs. In this paper we present the design and construction of a passive-stereo, four-wall CAVE system based on commodity hardware. Our system works with any mix of a wide range of projector models that can be replaced independently at any time, and achieves high resolution and brightness at a minimum cost. The key ingredients of our CAVE are a self-calibration approach that guarantees continuity across the screen, as well as a gesture-based interaction approach based on a clever combination of skeletal data from multiple Kinect sensors.Preprin

Efficient 3D Reconstruction, Streaming and Visualization of Static and Dynamic Scene Parts for Multi-client Live-telepresence in Large-scale Environments

Despite the impressive progress of telepresence systems for room-scale scenes with static and dynamic scene entities, expanding their capabilities to scenarios with larger dynamic environments beyond a fixed size of a few square-meters remains challenging. In this paper, we aim at sharing 3D live-telepresence experiences in large-scale environments beyond room scale with both static and dynamic scene entities at practical bandwidth requirements only based on light-weight scene capture with a single moving consumer-grade RGB-D camera. To this end, we present a system which is built upon a novel hybrid volumetric scene representation in terms of the combination of a voxel-based scene representation for the static contents, that not only stores the reconstructed surface geometry but also contains information about the object semantics as well as their accumulated dynamic movement over time, and a point-cloud-based representation for dynamic scene parts, where the respective separation from static parts is achieved based on semantic and instance information extracted for the input frames. With an independent yet simultaneous streaming of both static and dynamic content, where we seamlessly integrate potentially moving but currently static scene entities in the static model until they are becoming dynamic again, as well as the fusion of static and dynamic data at the remote client, our system is able to achieve VR-based live-telepresence at close to real-time rates. Our evaluation demonstrates the potential of our novel approach in terms of visual quality, performance, and ablation studies regarding involved design choices

Enhanced life-size holographic telepresence framework with real-time three-dimensional reconstruction for dynamic scene

Three-dimensional (3D) reconstruction has the ability to capture and reproduce 3D representation of a real object or scene. 3D telepresence allows the user to feel the presence of remote user that was remotely transferred in a digital representation. Holographic display is one of alternatives to discard wearable hardware restriction, it utilizes light diffraction to display 3D images to the viewers. However, to capture a real-time life-size or a full-body human is still challenging since it involves a dynamic scene. The remaining issue arises when dynamic object to be reconstructed is always moving and changes shapes and required multiple capturing views. The life-size data captured were multiplied exponentially when working with more depth cameras, it can cause the high computation time especially involving dynamic scene. To transfer high volume 3D images over network in real-time can also cause lag and latency issue. Hence, the aim of this research is to enhance life-size holographic telepresence framework with real-time 3D reconstruction for dynamic scene. There are three stages have been carried out, in the first stage the real-time 3D reconstruction with the Marching Square algorithm is combined during data acquisition of dynamic scenes captured by life-size setup of multiple Red Green Blue-Depth (RGB-D) cameras. Second stage is to transmit the data that was acquired from multiple RGB-D cameras in real-time and perform double compression for the life-size holographic telepresence. The third stage is to evaluate the life-size holographic telepresence framework that has been integrated with the real-time 3D reconstruction of dynamic scenes. The findings show that by enhancing life-size holographic telepresence framework with real-time 3D reconstruction, it has reduced the computation time and improved the 3D representation of remote user in dynamic scene. By running the double compression for the life-size holographic telepresence, 3D representations in life-size is smooth. It has proven can minimize the delay or latency during acquired frames synchronization in remote communications

Mutual Gaze Support in Videoconferencing Reviewed

Videoconferencing allows geographically dispersed parties to communicate by simultaneous audio and video transmissions. It is used in a variety of application scenarios with a wide range of coordination needs and efforts, such as private chat, discussion meetings, and negotiation tasks. In particular, in scenarios requiring certain levels of trust and judgement non-verbal communication, cues are highly important for effective communication. Mutual gaze support plays a central role in those high coordination need scenarios but generally lacks adequate technical support from videoconferencing systems. In this paper, we review technical concepts and implementations for mutual gaze support in videoconferencing, classify them, evaluate them according to a defined set of criteria, and give recommendations for future developments. Our review gives decision makers, researchers, and developers a tool to systematically apply and further develop videoconferencing systems in serious settings requiring mutual gaze. This should lead to well-informed decisions regarding the use and development of this technology and to a more widespread exploitation of the benefits of videoconferencing in general. For example, if videoconferencing systems supported high-quality mutual gaze in an easy-to-set-up and easy-to-use way, we could hold more effective and efficient recruitment interviews, court hearings, or contract negotiations