A robust digital image watermarking based on adaptive multifunctional scheme

Reversible watermarking is mostly fragile, it can restore the original image losslessly if there is no attack during transmission. However, in real life, it is impossible not to be attacked completely. Reversible watermarking loses reversibility and becomes meaningless if it is attacked maliciously. In order to overcome this drawback and broaden its application field, an adaptive multifunctional watermarking scheme is proposed which is a special reversible watermarking scheme, which can not only restore the original image losslessly when it meets no attacks, but also can approximately recover the original image when it encounters malicious attacks. In the paper, the original image is divided into non-overlapping 8 × 8 blocks. And then, each block is transformed by IDCT (Integer Discrete Cosine Transform). The recovery watermark is generated by the method of 2DPCA (2 Dimension Principal Component Analysis) and the authentication watermark is produced by the special algorithm. According to the proposed block mapping method, the watermarks are embedded into its far mapping block adaptively. Moreover, MC (mapping and compensation) method is proposed to avoid overflow and underflow problems. The experimental results show that the proposed scheme can achieve reversibility and recoverability while keeping the lower distortion and higher embedding capacity.