3D shape reconstruction from incomplete silhouettes in multiple frames

3D shapes are reconstructed from silhouettes obtained by multiple cameras with the volume intersection method. In recent work, methods of integrating silhouettes in time sequences have been proposed. The number of silhouettes can be increased by integrating silhouettes in multiple frames. The silhouettes of a rigid object in multiple frames are integrated with its rigid motion. This motion is often estimated with 3D feature points extracted from silhouettes. When the estimated motion has large error, shapes are reconstructed with missing parts. This error is given by the incomplete extraction of 3D feature points, which is caused by additional and missing regions of extracted silhouettes. We cannot prevent silhouettes from being extracted with the additional and missing regions in real environments. Here, we propose an intelligent method of integrating incomplete silhouettes where outcrop points, which are 3D feature points for estimating motion, play an important role. The reconstructed shape can be evaluated referring to how many outcrop points have been included in the reconstructed shape of another frame. Although the evaluation does not represent the accuracy of estimated motion directly, it does guarantee that outstanding parts will be preserved in the reconstructed shape. Silhouettes in multiple frames can be integrated with fewer missing and additional parts based on this evaluation.