Watermark detection

A method and arrangement for detecting a watermark in an information signal. The method may include the steps of computing the correlation (dk) of the watermark (Wi) and the information signal (e.g. an image Q) for a plurality of positions (k) of the watermark with respect to the information signal, and detecting whether at least one of the respective correlation values exceeds a given threshold. The step of detecting may include determining the standard deviation (sigmad) of the respective correlation values (dk), and setting the threshold to a given multiple (T) of the standard deviation. The multiple (T) is derived form a desired false alarm rate (watermark detected when there is none, or no watermark detected when there is one)

Implementation of a real-time digital watermarking process for broadcast monitoring on a TriMedia VLIW processor

The implementation of a real-time digital watermark embedder and detector for television broadcast monitoring is addressed. A TriMedia processor with 4 BOPS (billion operations per second) is used for a software implementation. The performance of the system is tested in a laboratory environment under real-time conditions. The results prove the feasibility of a professional broadcast surveillance system, which is the aim of a European Esprit project named VIVA (visual identity verification auditor)

Device for optically scanning a record carrier

A watermark detector is disclosed to judge whether multimedia content can be copied or not. The watermark detector examines the multimedia content and outputs a signal indicating whether a watermark is present or not. A decision variable indicating to which extent the watermark is present is determined, for example, the amount of correlation between the input signal and a reference copy of the watermark to be detected. The watermark is detected if the decision variable exceeds a predetermined threshold (y2). The detector also generates a random output signal for a predetermined range of decision values between the threshold (y2) and a further threshold (y1)