Dual Back-to-Back Kinects for 3-D Reconstruction

In this paper, we investigated the use of two Kinects for capturing the 3-D model of a large scene. Traditionally the method of utilising one Kinect is used to slide across the area, and a full 3-D model is obtained. However, this approach requires the scene with a significant number of prominent features and careful handling of the device. To tackle the problem we mounted two back-to-back Kinects on top of a robot for scanning the environment. This setup requires the knowledge of the relative pose between the two Kinects. As they do not have a shared view, calibration using the traditional method is not possible. To solve this problem, we place a dual-face checkerboard (the front and back patterns are the same) on top of the back-to-back Kinects, and a planar mirror is employed to enable either Kinect to view the same checkerboard. Such an arrangement will create a shared calibration object between the two sensors. In such an approach, a mirror-based pose estimation algorithm is applied to solve the problem of Kinect camera calibration. Finally, we can merge all local object models captured by the Kinects together to form a combined model with a larger viewing area. Experiments using real measurements of capturing an indoor scene were conducted to show the feasibility of our work.