Method and apparatus for superimposing a level changed spectrum spread additional information signal on a video signal

摘要

Visual influence on the reproduced image by the spectrum spread additional information signal can be controlled on the reproduced image by sequentially changing the level of the spectrum spread additional information signal with the predetermined pattern in each chip section on the occasion of superimposing, on the video signal, the spectrum spread additional information signal in which the additional information such as duplication preventing control information and copy right information, etc. is spectrum spread.