In order to decode a received digital signal which has been watermarked with a known watermark, at least part of the digital signal is decoded by using a parametrisable iterative decoder, the watermark is extracted from the decoded signal, the extracted watermark is compared with the known watermark,...http://www.google.de/patents/US7013023?utm_source=gb-gplus-sharePatent US7013023 - Method and device for sending and receiving digital images using an image watermark for decoding
