Novel algorithm of third party''s double watermark applied in image
一种新的第三方双重图像水印算法

This paper presented a novel algorithm of the third party's double watermark.The algorithm relied on the third party's timestamp and users' secret keys and authorization codes,produced a double watermark.Then it would be embedded into the discrete cosine transform coefficients exception of direct current in digital image blocks.Timestamp and ownership watermark detecting results could be provided separately.Simulation experiments and analysis work reveal that the algorithm sensitizes to embedding parameters...