ELECTRONIC WATERMARK INFORMATION EMBEDDING DEVICE, ELECTRONIC WATERMARK INFORMATION REPRODUCING DEVICE, AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To effectively prevent the removal of electronic watermark information that is made many times at quality non-deteriorating levels by combining already existing plentiful electronic watermark information removing methods. SOLUTION: A parameter converter 11 converts a desired parameter (for example, the offset value of a color difference signal DC) in inputted contents data with respect to each picture element at the position corresponding to the watermark embedding map of image data of the inputted contents data in accordance with a parameter value from a parameter generator 13. An electronic watermark mixer 2 embeds the parameter value and copyright information in the parameter-converted contents input data as electronic watermark information. The embedded watermark data thus obtained are recorded on a recording medium 17. When the electronic watermark information is removed from the embedded watermark data reproduced from the recording medium 17 by using an already existing technique, only parameter-converted and quality- deteriorated inputted contents data can be reproduced and, consequently, the copyright of the contents data can be protected.