Improved Guided Position Scrambling for Digital Watermarking

Two techniques which improve the guided position scrambling applied to digital watermarking are described. One is the correlation criterion which is used for deciding the most suitable marking position at the encoder. This criterion, whose hardware complexity is low, is equivalent to the one generally using watermark-to-document and noise ratio. The other is a method in which a watermark to have been embedded assumedly is not presented at the decoder. This can broaden the applications of guided position scrambling.