New range finder based on the re-encoding method and its application to 3D object modeling

We propose a novel range finding technique for measuring the 3D shape of objects. Experiments were carried out to verify the principle of this technique, and effectiveness of the technique was demonstrated through the experiments. The new range finding technique, which is based on a spatial encoding method, uses a single light pattern encoded with multiple values and enables the acquisition of range information of an object in a single shot. The conventional spatial encoding method uses a projector for projecting a light pattern onto an object and a CCD camera for measuring the 3D shape of the object. In this new technique, we use an additional CCD camera to cancel the influence of the texture of the object. The additional CCD camera is positioned so that the principal point and optical axis of the camera's lens become the same as those of the projector's lens. The light pattern projected onto the object is encoded again using image data captured by the additional CCD camera. Range image data acquired using this technique is highly accurate. We call this technique the Spatial Re-encoding method or SR method. We made an experimental model and captured range data of an object form different viewpoints to evaluate the effectiveness of the SR method. The whole 3D shape of the object was successfully built using those range data. This paper describes the new range finding technique called the SR method.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.