DIGITAL WATERMARK INFORMATION SUPERIMPOSING METHOD, DIGITAL WATERMARK INFORMATION TRANSMITTING METHOD, DIGITAL WATERMARK INFORMATION SUPERIMPOSING APPARATUS, AUTHORING APPARATUS AND VIDEO SIGNAL OUTPUT APPARATUS

摘要

A method and apparatus for superimposing digital watermark information to avideosignal are provided. The method comprises the steps of determining beforeconversion aformat of a video signal that is to have digital watermark informationsuperimposed thereonand determining a format of the video signal after conversion from said videosignal beforeconversion. A unit block size of the video signal before conversion is thendetermined thatincludes a whole number of pixels in both the horizontal and verticaldirections so that whensaid video signal before conversion is converted to the format of the videosignal afterconversion, a resulting unit block size of said video signal after conversionalso includes adifferent whole number of pixels in both the horizontal and verticaldirections. Theconversion is accompanied selectively by an interpolating process or athinning process in thehorizontal direction or the vertical direction or a time direction betweenconsecutive framesor fields.