Patent Document ID: 8502815
Application ID: 12596653
Patent Flag: 1

Claim One:
1. A method for encoding a time-consistent 3D mesh sequence using scalable predictive coding, the method comprising: receiving successive frames of a 3D mesh sequence, wherein a frame comprises a set of vertices (V) with associated connectivity (K) and wherein the connectivity (K) is identical for all frames of the 3D mesh sequence, decomposing the 3D mesh sequence into a multi-resolution representation comprising two or more spatial layers represented by disjoint sets of vertices (V l ) with associated connectivities (K l ), wherein the decomposing the 3D mesh sequence into a multi-resolution representation includes: setting a number of layers (L) for decomposition, encoding the set number of layers (L) for the decomposition, selecting one or more patches comprising sets of triangles having one middle vertex in common, the middle vertex having a valence not more than a predefined number, in particular not more than 6, the valence being defined by the number of direct neighbour vertices of said middle vertex, removing the middle vertices of said one or more selected patches and generating a decomposed layer (V L ) defined by said removed middle vertices with associated connectivity (K L ), determining a simplified connectivity associated to the remaining set of vertices, wherein the determining the simplified connectivity associated to the remaining set of vertices includes triangulating the vertices of the former 1-ring neighborhood of a removed vertex, wherein the 1-ring neighborhood is defined by all vertices being a direct neighbour of a vertex, wherein a triangulation is selected based on an average absolute deviation of the valences of the vertices of the 1-ring neighborhood of the removed vertex from a valence equal to a predefined number, in particular equal to 6 with respect to the triangulation and the connectivity (K l ) associated to the layer, repeating the selecting one or more patches, the removing the middle vertices, and the determining a simplified connectivity for a number of iterations (L−2) being by 2 less than the number of set layers on the respective remaining sets of vertices with associated simplified connectivities to generate decomposed layers (V L-1 ,. .. , V 2 ) with associated connectivities (K L-1 ,. .. , K 2 ), and defining the remaining set of vertices (V 1 ) associated connectivity (K 1 ) as a base layer, and encoding the vertices of the layers using a predictive encoder, wherein the decomposition is calculated from the connectivity (K) of the 3D mesh sequence irrespectively of location data of the vertices, and wherein the encoding the vertices of the layers using a predictive encoder includes: selecting a compression method for each frame being selected of the group comprising of: an I-frame compression and a P-frame compression and/or a B-frame compression, and generating a prediction error using an I-frame predictor a P-frame predictor, or a B-frame predictor respectively, wherein the P-frame compression includes, for a current vertex of a current frame, considering an already encoded frame as a reference frame, calculating P-frame predictor by adding up an I-frame predictor of the current vertex of the current frame and the difference of the location of the current vertex in the reference frame and an I-frame predictor of the current vertex of the reference frame respectively, whereby said difference is multiplied by a Rotation Matrix (A).