Thomson Licensing

Contentarmor

Gwenael Doerr

Antoine Robert

Pierre Alliez

Xavier Rolland-Neviere

Séverine Baudry

Cesar Burini

Omar Julian Alvarez Gomez

Javier Franco-Contreras

Omar Alvarez Gomez

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.

Method for watermarking a three-dimensional object

A method for preparing content for watermarking is disclosed. The content is available in different versions on a server for at least a client and the different versions of the content are subdivided into temporally aligned chunks. For each version of the content, candidate locations for watermarking are obtained. A watermark payload bit insertion rate is determined according to a minimum path. Watermark embedding metadata is generated for each version of the content such that the watermark payload bit insertion rate is the same. A device for implementing the method and a non-transitory program storage device are also disclosed.

Method for watermarking a content

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.

Method for watermarking a three dimensional object and method for obtaining a payload from a three dimensional object

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.

Method for inserting features into a three-dimensional object and method for obtaining features from a three dimensional object

A method for determining a set of modifiable elements in a group of pictures of a coded bit-stream representative of an audio video content is disclosed. The method comprises determining a set of a candidate modifiable elements wherein a candidate modifiable element comprises a modified value of the coded bit-stream and a spatial propagation map associated with the modified value, a spatial propagation map comprising pixels whose decoding is impacted when the modified value is placed in the coded bit stream; determining a heat map for each reference frame, the heat map comprising, for each pixel of the reference frame, an information representative of the usage of said pixel for temporal prediction during the decoding of said part of the coded bit-stream coding a group of pictures; obtaining a set of modifiable elements among candidate modifiable elements, a modifiable element having a spatial propagation map that does not overlap with corresponding heat map.

Method and device for determining a set of modifiable elements in a group of pictures

The invention relates to a method for assessing the presence of a watermark in a video wherein the video comprises at least a sequence of frames. The method comprises for at least one frame among one of the sequences of frames the steps of computing a set of axial cross-correlation values, wherein each axial cross-correlation value corresponds to a correlation between the frame and a reference watermark shifted along a spatial horizontal axis; obtaining a detection score by computing a weighted sum of values output by a function applied to said axial cross-correlation values; assessing the presence of a watermark according to the detection score. Such method is particularly well adapted to the detection of disparity coherent watermark but is compliant with any watermarking technique. A device implementing the method is further disclosed.

Method and device for assessing the presence of a watermark in a video

A device for generating metadata associated with a content intended to be watermarked with an identifier stored in a device for embedding a watermark is disclosed. The device for generating metadata comprises a processor configured to generate metadata. The metadata comprises (i) an instruction for deriving a current payload bit from the identifier wherein the current payload bit is determined from a lookup index wherein the instruction for deriving a current payload bit indicates to which position in the identifier corresponds the current payload bit, or from a XOR function applied to a plurality of bits of the identifier, wherein the instruction for deriving a current payload bit comprises a binary mask indicating which bits in the identifier corresponds to XORed bits.

Device for generating watermark metadata, associated device for embedding watermark

The invention relates to a method for watermark embedding in multi views video comprising a plurality of views captured with a plurality of cameras comprising for each view a step of projecting the view onto a domain invariant to the plurality of views and to intermediate synthesized view, which depends on the locations, orientations, and intrinsic parameters of the cameras, resulting into an invariant vector; a step of applying a watermarking algorithm to the invariant vector resulting into a watermarked invariant vector; and a step of modifying the view to obtain a watermarked view, wherein said watermarked view when projected onto the invariant domain results into the watermarked invariant vector. The invention also relates to a method for watermark detection in a rendered view comprising a step of projecting the rendered view onto an invariant domain to the plurality of views resulting into an invariant rendered vector; a step of applying a watermark detection algorithm to the invariant rendered vector in order to assess the presence of a watermark.

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Rennes, France

Gwenael Doerr