Octree-based animated geometry compression

Geometry compression is the coding of 3D geometric data in a form that requires less space to store and less bandwidth to transmit. This 3D geometric data provides a computer graphics system with the scene description necessary to render images. Geometric data is quite large and, therefore, needs effective compression methods to decrease the transmission and storage requirements. A large amount of research has been focused on static geometry compression, but only limited research has addressed animated geometry compression, the compression of temporal sequences of geometric data. The goal of this paper is to represent 3D animation sequences with a reduced set of motion vectors that take advantage of the large data coherence in space and time. We proposed an octree-based motion representation method in which a small set of motion vectors are generated for each frame by analyzing the motion between consecutive frames. The vectors represent the differential motion from a previous frame to the current frame and are used to predict the vertex positions for the new frame. The octree motion representation process generates a hierarchical octree structure for each frame in the sequence. The octree approach can represent 3D animated sequences with high compression factors while maintaining reasonable quality. This approach, is easy to implement and have a low cost encoding process and a fast decoding process, which make it very suitable for real time application. (C) 2007 Elsevier Ltd. All rights reserved.