A new semi-fragile image watermarking algorithm based on visual masking is proposed in this paper.On the basis of the visual masking of human visual system

the watermark can be adaptively embedded into host image in the wavelet domain by using group quantization in our algorithm.The proposed semi-fragile watermarking is effective for copyright protection and content authentication simultaneously without resorting to the original host image.Experimental results show that our semi-fragile watermarking scheme is invisible and is robust to common image processing(such as JPEG compression

noise adding

filtering). The proposed watermarking algorithm is fragile to content modification(such as cropping)

can detect effectively the tampered regions

and has a lower probability of missing and lower probabilities of a false alarm compared with other popular semi-fragile watermarking schemes.