SUPERIMPOSING METHOD FOR DIGITAL WATERMARK INFORMATION, TRANSMISSION METHOD FOR DIGITAL WATERMARK INFORMATION, SUPERIMPOSING DEVICE FOR DIGITAL WATERMARK INFORMATION, AUTHORING DEVICE AND VIDEO SIGNAL OUTPUT DEVICE

摘要

PROBLEM TO BE SOLVED: To simply and accurately detect digital watermark information superimposed on a video signal before and after it is converted. SOLUTION: A comparison arithmetic section 34 acquires format information of an input video signal (video signal before signal conversion) recorded in a digital video disk 100 from a before-signal-conversion format memory 33F and acquires estimated format information of the input video signal after signal conversion from an after-signal-conversion format memory 33B. The comparison arithmetic section 34 sets a size of a unit block that is a superimposing unit of a spread spectrum signal in the video signal before the signal conversion so that the digital watermark information superimposed on the video signal can accurately be detected from both the video signals before and after the signal conversion.