Restorable image authentication scheme based on fragile watermarking
Pla Information · 2007
Since existing fragile watermarking schemes usually cannot recover the tampered position,a restorable image authentication scheme is proposed.The image is divided into small blocks and each block is DCT(discrete cosine transform) transformed.A specified number of the lower frequency DCT coefficients are encoded using a fixed number of bits.The resulting bit string as the recovery watermarks are embedded into the second LSB(least significiant bit) of the corresponding excursion block,then the authentication watermarks of each block are embedded into its LSB.Theoretical analysis and simulation results show that the proposed algorithm can not only locate tampered blocks accurately,but also restore the tampered region effectively and ensure the system security.