METHOD OF ADDING INFORMATION TO VIDEO SIGNAL AND INFORMATION ADDING DEVICE

摘要

When a spectrally spread additional information signal, obtained by spectrum spreading additional information such as an anti-duplication control signal or copyright information, is superimposed on a video signal, the level of the spectrally spread additional information signal is controlled according to the scatter of pixel values in each block comprising plural pixels. The sensitivity of detecting additional information from the spectrally spread additional information signal is therefore improved, and the visual effect of the spectrally spread additional information signal on a reproduced image is suppressed.