Abstract: Selective data encryption of a file, in particular an H.264/MPEG-4 AVC data stream. If a first unit in the data stream is to be encrypted, it is encrypted and the encryption is put into a further unit, preferably in the data stream. A substitution unit is generated and put in the place of the first unit; if necessary, at least one header value is taken from the first unit for use in the substitution unit. A decryptor receives the encrypted data stream, extracts and decrypts the further unit and replaces the substitution unit with a regenerated first unit.

Abstract: 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.

Abstract: A method for inserting at least one message in a rendering of a video content by a display device is disclosed. The display device comprises a periodic light source and the method comprises obtaining one bit of the message and modulating a frequency of the periodic light source in view of the bit. A device for inserting at least one message is disclosed. In another aspect, a method and a device for reading at least one message in a video content obtained by filming a display device wherein the display device comprises a periodic light source whose frequency is modulated in view of a bit of the message is further disclosed.

Abstract: 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.

Abstract: A method for determining a modifiable element in a coded bit-stream is disclosed that comprises decoding a part of the coded bit-stream; modifying said part of the coded bit-stream; decoding the modified part of the coded bit-stream; and obtaining a modifiable element with an element in the decoded modified bit-stream in the case where the modified part of the coded bit-stream is compliant with the coded bit-stream; and where said element in the decoded modified bit-stream, called modifiable element, is different from an element in the decoded original bit-stream. A device for determining a modifiable element in a coded bit-stream is further disclosed.

Abstract: The invention relates to a method for decoding a watermark embedded in a video comprising blocks of samples representative of the video comprising the steps of determining in the video a location of a watermarked block; determining a location for each reference block among a plurality of reference blocks wherein a reference block is associated to a watermark value among a plurality of watermark values; comparing the watermarked block with each reference block; and identifying watermark value for the watermarked block from the results of the plurality of comparison. The method is remarkable in that each reference block is equally located in the video, for instance the pirated video, so that the plurality of comparisons between the watermarked block and each reference block is performed among the same video.

Abstract: The invention relates to a method for temporal video registration of a target video with a master video comprising steps of automatic selection a plurality of key frames for target video and a plurality of key frames for master video; sparse registration of a plurality of key frames for target video with a plurality of key frames for master video; dense registration of frames of target video with frames of master video belonging to a temporal segment including registered key frames.

Abstract: 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.

Abstract: A method for temporal registration of a first sequence of images and a second sequence of second images is described.

Abstract: Selective data encryption of a file, in particular an H.264/MPEG-4 AVC data stream. If a first unit in the data stream is to be encrypted, it is encrypted and the encryption is put into a further unit, preferably in the data stream. A substitution unit is generated and put in the place of the first unit; if necessary, at least one header value is taken from the first unit for use in the substitution unit. A decryptor receives the encrypted data stream, extracts and decrypts the further unit and replaces the substitution unit with a regenerated first unit.

Abstract: The invention relates to a method for decoding a watermark embedded in a video comprising blocks of samples representative of the video comprising the steps of determining in the video a location of a watermarked block; determining a location for each reference block among a plurality of reference blocks wherein a reference block is associated to a watermark value among a plurality of watermark values; comparing the watermarked block with each reference block; and identifying watermark value for the watermarked block from the results of the plurality of comparison. The method is remarkable in that each reference block is equally located in the video, for instance the pirated video, so that the plurality of comparisons between the watermarked block and each reference block is performed among the same video.

Abstract: The invention relates to a method of watermarking a binary stream resulting from the encoding of a set of coefficients comprising at least one coefficient encoded by predictive coding, called predictively coded coefficient. The method comprises the steps of: a) identifying, in the binary stream, a first binary word representing the predictively coded coefficient; b) computing a modified coefficient from the predictively coded coefficient on the basis of at least one watermarking bit; c) encoding the modified coefficient into a second binary word; and d) replacing in the binary stream the first binary word with the second binary word.

Abstract: The invention relates to a method of watermarking a binary stream resulting from the encoding of a set of coefficients comprising at least one coefficient encoded by predictive coding, called predictively coded coefficient. The method comprises the steps of: a) identifying, in the binary stream, a first binary word representing the predictively coded coefficient; b) computing a modified coefficient from the predictively coded coefficient on the basis of at least one watermarking bit; c) encoding the modified coefficient into a second binary word; and d) replacing in the binary stream the first binary word with the second binary word.

Abstract: The invention relates to a method for watermarking at least one timestamp in a set of support data, comprising the following steps for each timestamp: association with the timestamp of the value at a given time of a reference timestamp signal, that is a determinist signal varying over time in a given temporal reference and being written as s(t), wherein t is incremented according to an incrementing step equal to one predetermined time unit; and watermarking of the value in the set of support data.

Abstract: 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.

Abstract: The invention relates to a method for temporal video registration of a target video with a master video comprising steps of automatic selection a plurality of key frames for target video and a plurality of key frames for master video; sparse registration of a plurality of key frames for target video with a plurality of key frames for master video; dense registration of frames of target video with frames of master video belonging to a temporal segment including registered key frames.

Abstract: The invention relates to a method of watermarking a data set comprising the steps of: selecting, in the data set, at least one group of two data; and modifying at least one data of the group. The data is modified such that the difference between the modified data and the other data of the group possibly modified equals a predefined watermarking parameter multiplied by an integer number, called rejection class, associated with the group and equal to the integer nearest to the ratio between the difference between the at least one data and the other data of the group before the modification divided by the watermarking parameter.

Abstract: A method for temporal registration of a first sequence of images and a second sequence of second images is described.

Abstract: The invention relates to a method of reading a watermark, of the type comprising a step of determining at least one watermarking message contained in a data set, possibly preceded by a step of determining at least one suite of parameters of a watermarking channel undergone by the data set, each suite of channel parameters comprising at least one channel parameter. The step of determining at least one watermarking message and/or the prior step of determining at least one suite of channel parameters comprises (comprise): an estimation phase, consisting in processing at least one batch of data comprising data of the data set, so as to obtain N estimated element(s), with N?0; and a verification phase, consisting in validating or invalidating, in view of the entirety or of at least a subset of the data set, each estimated element.

Abstract: The invention relates to a method of watermarking a data set comprising the steps of: selecting, in the data set, at least one group of two data; and modifying at least one data of the group. The data is modified such that the difference between the modified data and the other data of the group possibly modified equals a predefined watermarking parameter multiplied by an integer number, called rejection class, associated with the group and equal to the integer nearest to the ratio between the difference between the at least one data and the other data of the group before the modification divided by the watermarking parameter.