So this paper puts forward the research approach of color images watermarking based on DWT, this method can increase the protection information and expand and the hiding range.

• 本文首先研究了国内外数字水印发展的现状,介绍了数字水印技术的基本特点和模型,分析了常见的数字水印算法,归纳了数字水印的攻击方法和认证手段。