二维工程图中基于分数傅里叶变换的盲水印算法

提出了一种基于二维工程图的水印算法。该方法提取二维工程图中线段的相对坐标向量,构造一维复数信号。通过分数傅里叶变换得到复数信号的变换系数,根据水印的大小和分数傅里叶变换系数的之间的关系,对变换系数的幅值进行调整来嵌入水印。该方法是盲水印算法,在提取水印时不需要原始工程图。实验表明,该算法对平移、旋转、缩放等攻击具有良好的鲁棒性,同时具有良好的安全性。

Blind watermarking algorithm for 2D engineering graphics based on fractional Fourier transform

A new method of digital watermarking for two-dimensional engineering graphics was proposed, In this method, the relative coordinate vectors of the lines were extracted from 2D engineering graphics for constructing a 1D complex signal. Watermark was embedded into the module of fractional Fourier transform coefficients of the complex signal based on the relationship between the values of watermark and transform coefficients. It is a blind watermarking algorithm due to the fact that watermark can be extracted without original engineering graphic. Experimental results show that the proposed algorithm is robust against the attacks such as moving, rotation, scaling, and is also safe towards illegal information extraction.