二元纯位相滤波器与半脆弱数字图像水印

Binary Phase-Only Filter and Semi-Fragile Digital Image Watermarking

文章分析了一种由F.Ahmed和I.S.Moskowitz提出的基于二元纯位相滤波器(BPOF)的半脆弱数字图像水印技术。该算法作用在图像Fourier变换域,将BPOF作为水印嵌入到幅值中。其优点在于以图像内在特征(即BPOF)作为水印,不需要传递大量额外数据用于图像认证。该文着重讨论了原始图像BPOF,嵌入水印后图像BPOF,嵌入水印后图像幅值三者之间相互关系,并分析了算法的稳健性,其结论有助于该类算法的进一步改进。

A Binary Phase-Only Filter（BPOF） based semi-fragile digital watermarking technique proposed by F.Ahmed and I.S.Moskowitz is analyzed.In the Fourier domain of the image,the BPOF is embedded into the magnitude.This technique takes the inherent characteristics of the image（here is BPOF） as watermark,thus it is not necessary to transmit a lot of data for image authentication.We emphasize our discussions on the relations among the BPOF of the original image,the BPOF of the watermarked image and the magnitude of the watermarked image as well as the robustness of the algorithm.The results will benefit the further improvement of such kind technique.