基于视觉掩蔽的半脆弱水印技术研究

以人眼视觉系统的掩蔽特性为基础,提出了一种基于分组量化的自适应半脆弱水印嵌入方案,该方案能够在不参考原始载体的情况下对数字图像同时进行版权保护和内容认证。仿真实验结果表明,所提出的半脆弱水印方案不仅具有较好的透明性,对JPEG压缩、叠加噪声、平滑滤波等常规图像处理操作具有较好的鲁棒性,而且能够对剪切、替换等恶意图像篡改做出报警并确定被篡改位置。同时常规图像处理下其误检率与漏检率均比较低。

A New Semi-fragile Image Watermarking Based on Visual Masking

A new semi-fragile image watermarking algorithm based on visual masking is proposed in this paper.On the basis of the visual masking of human visual system,the watermark can be adaptively embedded into host image in the wavelet domain by using group quantization in our algorithm.The proposed semi-fragile watermarking is effective for copyright protection and content authentication simultaneously without resorting to the original host image.Experimental results show that our semi-fragile watermarking scheme is invisible and is robust to common image processing(such as JPEG compression,noise adding,filtering). The proposed watermarking algorithm is fragile to content modification(such as cropping),can detect effectively the tampered regions,and has a lower probability of missing and lower probabilities of a false alarm compared with other popular semi-fragile watermarking schemes.