Speaker: Diego Thomas (JFLI & NII)
Date: 28th February 2013
Place: room 214, Faculty of Science Bldg. 7, Hongo Campus, The University of Tokyo
Recently, a significant effort has been made to develop inexpensive consumer depth cameras that allow the acquisition of depth images at a video rate, e.g., Microsoft Kinect. The video-rate depth cameras are becoming a commodity tool for depth measurement with reasonable accuracy. Such a depth camera brings a new problem setting for 3D reconstruction: how to efficiently and accurately register (i.e. align) a dense set of depth images taken from continuously varying viewpoints. We present a robust and accurate 3D registration method for a dense sequence of depth images taken from unknown viewpoints. Our method simultaneously estimates multiple extrinsic parameters of the depth images to obtain a registered full 3D model of the scanned scene. By arranging the depth measurements in a matrix form, we formulate the problem as a simultaneous estimation of multiple extrinsics and a low-rank matrix, which corresponds to the aligned depth images as well as a sparse error matrix. Unlike previous approaches that use sequential or heuristic global registration approaches, our solution method uses an advanced convex optimization technique for obtaining a robust solution via rank minimization. To achieve accurate computation, we develop a depth projection method that has minimum sensitivity to sampling by reading projected depth values in the input depth images. We demonstrate the effectiveness of the proposed method through extensive experiments and compare it with previous standard techniques.