ELECTRONIC WATERMARK TO ONE-DIMENSIONAL DATA

摘要

PROBLEM TO BE SOLVED: To reduce the occurrence of noise due to burying of watermark information and to improve the secrecy of watermark information. SOLUTION: At the time of burying watermark information in original one- dimensional data, a PN series g(t) is used to generate a first spread one- dimensional data x(t) by spectrum spread. Next, this first spread one-dimensional data x(t) is subjected to modified discrete cosine transformation. The value of a specific frequency component of the MDCT coefficient is so adjusted that it corresponds to watermark information. This adjusted frequency component is inversely converted to generate second spread one-dimensional data x'(t), and finally, the same PN series as spreading is used to generate electronic watermark one-dimensional data, where watermark information is buried, by spectrum inverse spreading.