View Synthesis: LiDAR Camera versus Depth Estimation

Depth-Image-Based Rendering (DIBR) can synthesize a virtual view image from a set of multiview images and corresponding depth maps. However, this requires an accurate depth map estimation that incurs a high compu- tational cost over several minutes per frame in DERS (MPEG-I’s Depth Estimation Reference Software) even by using a high-class computer. LiDAR cameras can thus be an alternative solution to DERS in real-time DIBR ap- plications. We compare the quality of a low-cost LiDAR camera, the Intel Realsense LiDAR L515 calibrated and configured adequately, with DERS using MPEG-I’s Reference View Synthesizer (RVS). In IV-PSNR, the LiDAR camera reaches 32.2dB view synthesis quality with a 15cm camera baseline and 40.3dB with a 2cm baseline. Though DERS outperforms the LiDAR camera with 4.2dB, the latter provides a better quality-performance trade- off. However, visual inspection demonstrates that LiDAR’s virtual views have even slightly higher quality than with DERS in most tested low-texture scene areas, except for object borders. Overall, we highly recommend using LiDAR cameras over advanced depth estimation methods (like DERS) in real-time DIBR applications. Neverthe- less, this requires delicate calibration with multiple tools further exposed in the paper.

Do You Need to Travel? Mapping Face-to-Face Communication Objectives to Technology Affordances

Computer-mediated communications (CMC) can be used as a substitute for face-to-face (FtF) meetings but their effectiveness is highly context dependent. This paper describes a theoretical framework and initial experimental design for characterizing a travel replacement threshold. This effort begins with a use case of remote engineering maintenance training, conducted in three conditions: side-by-side (physically proximate), teleconference (using off-the-shelf software), and a custom VR/AR system designed to provide the apprentice with a virtual view of both the instructor’s larger scale lab and smaller scale workbench. The research hypotheses, experimental protocol, and dependent measures are described. The task involves an instructor demonstrating a circuit board troubleshooting task to a remote apprentice. The apprentice then completes the trained task independently, and performance and subject preferences are compared across conditions. The details of this paper, the result of extensive literature review and winnowing of variables, may assist researchers exploring CMC, training, or social communication.