| 摘要 |
PROBLEM TO BE SOLVED: To specify a watermarked material item with high probability and to lower the probability of missing. SOLUTION: One code word in a set of prescribed code words is introduced to a copy of an original material item, and a watermarked version of the original material item is created. The code word is generated by a pseudo random number generator which is initialized by a seed value. The seed value is used for the purpose of specifying the watermarked material item from the code word generated by the seed value. The code word is reproduced from the watermarked material item, all code words in the set of code words are made correlative with a reproduced code word, and the specific copy of the watermarked material item is detected. COPYRIGHT: (C)2004,JPO |
