Method and apparatus for recording and reproducing electronic watermark information, and recording medium

摘要

When a video signal having electronic watermark information embedded therein is recorded on a recording medium, a reference signal is inserted in the video signal at a position different from a position of embedment of the electronic watermark information. The electronic watermark information is embedded in the video signal by alteration of a luminous value of a luminance signal included in the video signal. When the video signal is reproduced from the recording medium, a luminous value of the electronic watermark information is modified based on the reference signal.