A new 3D representation and compression algorithm for non-rigid moving objects using affine-octree

This paper presents a new 3D representation for non-rigid objects using motion vectors between two consecutive frames. Our method relies on an octree to recursively partition the object into smaller parts for which a small number of motion parameters can accurately represent that portion of the object. The partitioning continues as long as the respective motion parameters are insufficiently accurate to describe the object. Unlike other octree methods, our method employs an affine transformation for the motion description part, which greatly reduces the storage. Finally, an adaptive thresholding, a singular value decomposition for dealing with singularities, and a quantization and arithmetic coding further enhance our proposed method by increasing the compression while maintaining very good signal-noise ratio. Compared with other methods like tri-linear interpolation or principle component analysis (PCA) based algorithm, the affine-octree method is easy to compute and highly compact. As the results demonstrate, our method has a better performance in terms of compression ratio and PSNR, while it remains simple.