Watermarking an information signal

摘要

A multi-bit watermark is detected in a signal (e.g. a video image) in which each bit of the multi-bit value is represented by an embedded watermark subpattern in the signal. The watermark is detected by first detecting the presence of the full watermark in the signal irrespective of its multi-bit value, and then detecting to which extent the presence of subpatterns corresponds with the multi-bit value to be checked.