Progressive encoding and adaptive reconstruction of dynamic meshes using zerotree coding

A method for progressively decoding a mesh, comprising:

• obtaining a zerotree bitstream, coding, by a zerotree bitstream syntax, displacement data representative of a spatial difference between a base mesh and the mesh;
• zerotree decoding, from the zerotree bitstream, wavelet coefficients in a traversal order according to a zerotree hierarchy, the wavelet coefficients are computed at multiple resolution levels associated with respective mesh subdivisions representative of the mesh, wherein a significance flag is turned on, if one or more wavelet coefficients of a respective dimension, of the computed wavelet coefficients, are labeled as positive significant coefficients or as negative significant coefficients during the zerotree encoding;
• and
• inverse transforming the decoded wavelet coefficients into decoded displacement data.

An apparatus for progressively encoding a mesh, comprising:

• at least one processor;
• and
• memory storing instructions that, when executed by the at least one processor, cause the apparatus to:
• obtain displacement data, representative of a spatial difference between a base mesh and the mesh,
• transform the displacement data into wavelet coefficients, computed at multiple resolution levels associated with respective mesh subdivisions representative of the mesh, and
• zerotree encode the wavelet coefficients in a traversal order according to a zerotree hierarchy, wherein the zerotree encoding generates, by a zerotree bitstream syntax, a zerotree bitstream of coded displacement data, and wherein a significance flag is turned on, if one or more wavelet coefficients of a respective dimension, of the computed wavelet coefficients, are labeled as positive significant coefficients or as negative significant coefficients during the zerotree encoding.

An apparatus for progressively decoding a mesh, comprising:

• at least one processor;
• and
• memory storing instructions that, when executed by the at least one processor, cause the apparatus to:
• obtain a zerotree bitstream, coding, by a zerotree bitstream syntax, displacement data representative of a spatial difference between a base mesh and the mesh,
• zerotree decode, from the zerotree bitstream, wavelet coefficients in a traversal order according to a zerotree hierarchy, the wavelet coefficients are computed at multiple resolution levels associated with respective mesh subdivisions representative of the mesh, wherein a significance flag is turned on, if one or more wavelet coefficients of a respective dimension, of the computed wavelet coefficients, are labeled as positive significant coefficients or as negative significant coefficients during the zerotree encoding, and
• inverse transform the decoded wavelet coefficients into decoded displacement data.

A non-transitory computer-readable medium comprising instructions executable by at least one processor to perform a method for progressively encoding a mesh, the method comprising:

• obtaining displacement data, representative of a spatial difference between a base mesh and the mesh;
• transforming the displacement data into wavelet coefficients, computed at multiple resolution levels associated with respective mesh subdivisions representative of the mesh;
• and
• zerotree encoding the wavelet coefficients in a traversal order according to a zerotree hierarchy, wherein the zerotree encoding generates, by a zerotree bitstream syntax, a zerotree bitstream of coded displacement data, and wherein a significance flag is turned on, if one or more wavelet coefficients of a respective dimension, of the computed wavelet coefficients, are labeled as positive significant coefficients or as negative significant coefficients during the zerotree encoding.

A non-transitory computer-readable medium comprising instructions executable by at least one processor to perform a method for progressively decoding a mesh, the method comprising:

• obtaining a zerotree bitstream, coding, by a zerotree bitstream syntax, displacement data representative of a spatial difference between a base mesh and the mesh;
• zerotree decoding, from the zerotree bitstream, wavelet coefficients in a traversal order according to a zerotree hierarchy, the wavelet coefficients are computed at multiple resolution levels associated with respective mesh subdivisions representative of the mesh, wherein a significance flag is turned on, if one or more wavelet coefficients of a respective dimension, of the computed wavelet coefficients, are labeled as positive significant coefficients or as negative significant coefficients during the zerotree encoding;
• and
• inverse transforming the decoded wavelet coefficients into decoded displacement data.