Abstract: The present invention aims to overcome drawbacks of conventional content tracing methods requiring re-processing the content before its broadcast with a significant side channel transmission i.e. extra processing, storage and/or bandwidth at the distribution side, or alternately a complex signal processing implementation at the receiver side that has to be protected against hackers attacks. An efficient system and method consists of tracing and uniquely identifying decoders of a video stream wherein the decoders implement at least one variant of a standard image decompression algorithm and wherein the resulting decompressed image approximation varies according to the decoders' identifier.

Abstract: A method and a system for recognizing, by a broadcasting platform, content sequences of an input linear content stream by retrieving content information determined by small fingerprints of portions of the linear content and comparing the small fingerprint with reference fingerprints stored in a database. The output stream transmitted to the user units is modified by the addition of a synchronization stream including at least identifiers of the content sequences and associated temporal information determined on the basis of the reference fingerprints. The content information is exploited by the broadcasting platform or the users units for replacing a sequence by anther one, removing predefined sequences, skipping or forcing viewing content sequences, The initial linear content stream is thus enriched with accurate content information allowing the viewer to navigate and select the content to play either in live or replay mode.

Abstract: The present invention aims to overcome drawbacks of conventional content tracing methods requiring re-processing the content before its broadcast with a significant side channel transmission i.e. extra processing, storage and/or bandwidth at the distribution side, or alternately a complex signal processing implementation at the receiver side that has to be protected against hackers attacks. An efficient system and method consists of tracing and uniquely identifying decoders of a video stream wherein the decoders implement at least one variant of a standard image decompression algorithm and wherein the resulting decompressed image approximation varies according to the decoders' identifier.

Abstract: The invention relates in particular to a method of scrambling a video signal using an encryption key for controlling access to audiovisual information. The video signal is scrambled by applying a tattooing function to the video signal by using a marking key derived from the encryption key, the tattooing function including a parameter for regulating the amplitude of tattooing so as to enable the visibility of the tattooing in the video signal to be adjusted. The invention also provides a dual unscrambling method, and a system, an encoder, a decoder, a broadcast server, and a data medium for implementing said methods.

Abstract: This method comprises the following steps of applying a watermarking function to motion vectors calculated by estimation of movement between images of a video signal, followed by a step of generating the watermarked video signal by compensating movement with the aid of the watermarked motion vectors. The watermarking function is applied by marking the coordinates of the selected motion vector in a reference space, certain portions of this space constituting a first zone and the other portions of this space constituting a second zone complementary to the first, assigning a binary value to each of the two zones, and, if necessary, modifying the coordinates of the selected motion vector so that it is in the zone whose binary value corresponds to a bit of a marking key associated with the selected motion vector.

Abstract: A method for the watermarking of a sequence of video images implements a step for the insertion of at least one watermarking bit into at least one motion vector obtained by motion estimation between two images of said sequence, so as to obtain at least one watermarked motion vector. The motion vector is identified by its coordinates in a reference space, partitioned into two types of complementary zones, each having a distinct binary value associated with it. The insertion step implements, if necessary, a modification of the coordinates of said motion vector so that it is located in a binary value zone corresponding to said watermarking bit to be inserted. During said modification, at least two potential watermarked motion vectors are determined and, from among said potential watermarked motion vectors, an optimal watermarked motion vector is selected according to at least one predetermined criterion, so that the modified coordinates of said motion vector are those of said optimal watermarked motion vector.

Abstract: A method for the watermarking of a sequence of video images implements a step for the insertion of at least one watermarking bit into at least one motion vector obtained by motion estimation between two images of said sequence, so as to obtain at least one watermarked motion vector. The motion vector is identified by its coordinates in a reference space, partitioned into two types of complementary zones, each having a distinct binary value associated with it. The insertion step implements, if necessary, a modification of the coordinates of said motion vector so that it is located in a binary value zone corresponding to said watermarking bit to be inserted. During said modification, at least two potential watermarked motion vectors are determined and, from among said potential watermarked motion vectors, an optimal watermarked motion vector is selected according to at least one predetermined criterion, so that the modified coordinates of said motion vector are those of said optimal watermarked motion vector.

Abstract: The method comprises the following steps:

Abstract: The invention relates in particular to a method of scrambling a video signal using an encryption key for controlling access to audiovisual information. The video signal is scrambled by applying a tattooing function to the video signal by using a marking key derived from the encryption key, the tattooing function including a parameter for regulating the amplitude of tattooing so as to enable the visibility of the tattooing in the video signal to be adjusted. The invention also provides a dual unscrambling method, and a system, an encoder, a decoder, a broadcast server, and a data medium for implementing said methods.