| 摘要 |
An electronic watermark embedding apparatus includes means for storing a pixel matrix G with n rows and m columns of an input image, means for acquiring singular values s1 to sr, left singular vectors u1 to ur and right singular vectors v1 to vr of the pixel matrix G, means for creating a watermark information matrix W with r rows and r columns having a non-0 value as at least one nondiagonal element as electronic watermark information, creating a diagonal matrix S having singular values s1 to sr as diagonal elements, and creating a matrix Sw on the basis of Sw=S+aW (a≠0). The apparatus also includes means for multiplying the matrix Sw by a matrix U having the acquired left singular vectors u1 to ur as columns from the left and multiplying the transposed matrix of a matrix V having the acquired right singular vectors v1 to vr as columns from the right to create a pixel matrix Gw with n rows and m columns, and outputting it as an electronic-watermark-embedded image of the input image.
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