Image signal transmitting method, superimposed signal extracting method, image signal output apparatus, image signal receiving apparatus and image signal recording medium

摘要

A method and apparatus for superimposing additional information, such as duplication control information, on an image signal made up of first pictures encoded without using a predictive encoding and second picture encoded using a motion compensating prediction. Codes are generated with a timing based on an appearance of the first picture and then the additional information is superimposed on the image signal using the generated codes. The additional information already superimposed on such an image signal can be extracted in a similar fashion by generating codes based on the appearance of the first picture.