Abstract: A method for watermarking a three-dimensional object is disclosed. The three-dimensional object is represented by a mesh. A mesh comprises a plurality of vertices. The method further comprises computing an original thickness signature for said mesh from a plurality of thickness values, wherein a thickness value is computed for a vertex of the mesh; determining a target thickness signature, wherein the target thickness signature is a function of a watermark payload and of the original thickness signature; and modifying a position of at least one vertex of the mesh wherein a thickness signature computed for the modified mesh reaches the target thickness signature and wherein a distortion constraint between the mesh and the modified mesh is satisfied. A method for detecting a watermark in a three-dimensional object, a three-dimensional object carrying a watermark and, devices for implementing the methods are further disclosed.

Abstract: A method for watermarking a three-dimensional object is disclosed. The watermarking method comprises computing shape descriptor of a local neighborhood of a current vertex among the plurality of vertices of the three-dimensional object; obtaining a target shape descriptor from the shape descriptor using a quantization grid associated with a watermark payload; and modifying said local neighborhood wherein a position of at least one vertex of said local neighborhood is modified such that a shape descriptor of said modified local neighborhood is close to said target shape descriptor and wherein said current vertex is not modified. A method for obtaining payload from a three-dimensional object, a 3D object carrying a watermark and devices implementing the disclosed methods are further disclosed.

Abstract: A method for inserting features into a three-dimensional object is disclosed, wherein features correspond to original features of the three-dimensional object. The inserting method comprises determining a reference shape using the original features; determining a set of vertices on the three-dimensional original object at the intersection between the reference shape and the three-dimensional object; modifying the local neighborhood of the set of vertices so that their local neighborhood is close to a set of target shapes. A method for obtaining features from a three-dimensional object is further disclosed. The method comprises obtaining anchor vertices whose local neighborhood is close to a set of target shapes; fitting a reference shape onto the anchor vertices; and obtaining the features using the fitted reference shape. A 3D object carrying anchor vertices and devices for implementing the disclosed methods are further disclosed.

Abstract: A method for watermarking a three-dimensional object is disclosed. The three-dimensional object is represented by a mesh. A mesh comprises a plurality of vertices. The method further comprises computing an original thickness signature for said mesh from a plurality of thickness values, wherein a thickness value is computed for a vertex of the mesh; determining a target thickness signature, wherein the target thickness signature is a function of a watermark payload and of the original thickness signature; and modifying a position of at least one vertex of the mesh wherein a thickness signature computed for the modified mesh reaches the target thickness signature and wherein a distortion constraint between the mesh and the modified mesh is satisfied. A method for detecting a watermark in a three-dimensional object, a three-dimensional object carrying a watermark and, devices for implementing the methods are further disclosed.

Abstract: A method for watermarking a three-dimensional object is disclosed. The watermarking method comprises computing shape descriptor of a local neighborhood of a current vertex among the plurality of vertices of the three-dimensional object; obtaining a target shape descriptor from the shape descriptor using a quantization grid associated with a watermark payload; and modifying said local neighborhood wherein a position of at least one vertex of said local neighborhood is modified such that a shape descriptor of said modified local neighborhood is close to said target shape descriptor and wherein said current vertex is not modified. A method for obtaining payload from a three-dimensional object, a 3D object carrying a watermark and devices implementing the disclosed methods are further disclosed.

Abstract: A method for inserting features into a three-dimensional object is disclosed, wherein features correspond to original features of the three-dimensional object. The inserting method comprises determining a reference shape using the original features; determining a set of vertices on the three-dimensional original object at the intersection between the reference shape and the three-dimensional object; modifying the local neighborhood of the set of vertices so that their local neighborhood is close to a set of target shapes. A method for obtaining features from a three-dimensional object is further disclosed. The method comprises obtaining anchor vertices whose local neighborhood is close to a set of target shapes; fitting a reference shape onto the anchor vertices; and obtaining the features using the fitted reference shape. A 3D object carrying anchor vertices and devices for implementing the disclosed methods are further disclosed.

Abstract: A method for watermarking a three-dimensional object is disclosed wherein the three-dimensional object is represented by a mesh and a mesh comprises a plurality of vertices. The method comprises determining an original histogram of distances for said mesh, wherein a distance is computed between a barycenter of said mesh and a vertex of said mesh; modifying positions of a plurality of vertices of the mesh such that an histogram of distances for said modified mesh reaches a target histogram, said target histogram being a function of a watermark payload and of the original histogram of distances, wherein modifying the positions of said plurality of vertices comprises modifying the position of at least one vertex along a direction distinct from the direction defined by said vertex to the barycenter such that a distortion constraint between said mesh and said modified mesh is satisfied and such that a distortion constraint between said barycenter and a barycenter of said modified mesh is satisfied.

Abstract: A method for classifying projection recaptures is disclosed. A copy of a video content is classified as recorded from the digital projection of the video content, or as recorded from the projection of the celluloid film print of the video content by an automated method comprising classifying as a function of at least one feature extracted from a digital representation of the copy, among (i) spatial illumination uniformity; (ii) on-screen vertical stability; and (iii) temporal illumination pulse.