Abstract: The invention relates to a method, a device, a client-server system as well as a computer program product and computer program element for handling digital silence when fingerprinting digital media signals. A fingerprint comprising a number of sub-fingerprints for at least a part of the digital media signal is generated, (step 42), and the influence of at least one piece of the media signal on the fingerprint is removed or changed, (step 48), which piece corresponds to digital silence. The invention in a reliable way avoids a wrong identification of media signals, such as audio signals, where digital silence is included. The invention is also easy to implement by only requiring some of the functionalities already provided in a computer.

Abstract: A monitoring station (200) for monitoring distribution of media content, on basis of a watermark, comprises: receiving means (202) for receiving an information signal representing the media content to which the watermark is added; extracting means (204) for extracting perceptual features, identifying the information signal; first retrieving means (206) for retrieving a supporting signal on basis of the perceptual features; second retrieving means (208) for retrieving the watermark on basis of the supporting signal; and comparing means (210) for comparing the watermark with predetermined information.

Abstract: An undesirable side effect of watermarking or data-hiding schemes is that the host signal is distorted. This invention discloses a reversible or lossless data-hiding scheme, which allows complete and blind (without additional signaling) reconstruction of the host signal (X). This is achieved by accommodating, in the embedded data (d) of the watermarked signal (Y), restoration data (r) that identifies the host signal, given the composite signal, i.e. the restoration data identifies (24) which modifications the host signal has undergone during embedding (23). The restoration data is accommodated in a portion of the embedding capacity of a conventional embedder (23). The remainder of the capacity is used for embedding payload (w).