Extraction of outcrop points from visual hulls for motion estimation

In this article, we discuss 3D shape reconstruction of an object in a rigid motion with the volume intersection method. When the object moves rigidly, the cameras change their relative positions to the object at every moment. To estimate the motion correctly, we propose new feature points called outcrop points on the reconstructed 3D shape. These points are guaranteed to be located on the real surface of the object. If the rigid motion of the object can be correctly estimated, cameras at different moments serve as the cameras in different positions virtually. With these cameras in time sequences, we can increase accuracy of the reconstructed 3D shape without increasing the number of cameras. Based on this idea, we reconstruct an accurate shape of the object in motion from images obtained by limited number of cameras. As the result, we can acquire an accurate shape from images in time sequences.