초록 ▼

In the process of embedding watermark information in one-dimensional source data, first spread one-dimensional data x(t) is generated by subjecting one-dimensional source data s(t) to spectrum-spreading operation using a PN sequence g(t). This first spread one-dimensional data x(t) then undergoes a

In the process of embedding watermark information in one-dimensional source data, first spread one-dimensional data x(t) is generated by subjecting one-dimensional source data s(t) to spectrum-spreading operation using a PN sequence g(t). This first spread one-dimensional data x(t) then undergoes a modified discrete cosine transformation. A specific frequency component value of the MDCT coefficients is modulated to provide association with the watermark information. The modulated frequency component then undergoes inverse transformation to generate second spread one-dimensional data x'(t). Then, using the same PN sequence in the spreading, the second spread one-dimensional data is subjected to spectrum-despreading to produce digitally watermarked one-dimensional data in which watermark data has been embedded.

대표청구항 ▼

1. A method for embedding watermark information in one-dimensional source data, comprising the steps of:(a) performing spectrum-spreading by an operation equivalent to multiplying the one-dimensional source data by a specific positive/negative value sequence that randomly assumes positive/negative v

1. A method for embedding watermark information in one-dimensional source data, comprising the steps of:(a) performing spectrum-spreading by an operation equivalent to multiplying the one-dimensional source data by a specific positive/negative value sequence that randomly assumes positive/negative values having a specific absolute value, thereby generating first spread one-dimensional data; (b) subjecting the first spread one-dimensional data to orthogonal transformation; (c) modulating a specific frequency component value of transform coefficients obtained through the orthogonal transformation to provide association with the watermark information; (d) subjecting the modulated frequency component to inverse orthogonal transformation to generate second spread one-dimensional data; and (e) performing spectrum-despreading on the second spread one-dimensional data using the specific positive/negative value sequence to generate digitally watermarked one-dimensional data in which the watermark information has been embedded.