Abstract: A robust watermarking authentication algorithm with the value of visual masking as the quantization size is proposed.The security of it depends on hiding keys instead of quantization steps,which can be published,so that it could avoid some security gaps when using human visual characteristics.The fundamental advantage of our technique lies in its ability to distinguish common image processing from telltale tampering,and to tell what processing the image was made for the common image processing based on the error image of watermarks.Finally discussed in detail,the proposed algorithm and simulation results are given.

Key words: robust watermarks, value of visual masking