Evaluating the Similarity Degree of Digital Watermarks

摘要

The popular formulas currently used to evaluate the similarity of digital watermarks have serious drawbacks : when the similarity degree is 1, the watermarks are not unique. This paper firstly analyze the drawbacks in the popular formulas .then proposes a new formula similarity degree, which eliminates the shortcomings of the existing formulas and overcome the lack of uniqueness in theory,. Prom the experiment results the new formula not only does well in evaluating the watermark's similarity degree,also is in good accordance with visual perception.