摘要： 提出一种多小波域可恢复半脆弱数字水印算法。将缩小的原图像半色调图置乱后作为水印，采用分块自适应量化索引调制将水印嵌入到图像多小波域的低频系数中；利用被篡改的图像半色调图和提取水印的差异进行篡改定位；通过提取水印的逆半色调图实现篡改区域的近似恢复。仿真实验结果表明，该算法有效，且篡改定位精度较高。

关键词: 半脆弱数字水印, 多小波, 半色调技术, 篡改恢复

Abstract: A novel recoverable semi-fragile digital watermark algorithm in multiwavelet domain is proposed. The algorithm employs a reduced halftoned image as watermark and embeds it in the multiwavelet domain through adaptive quantization index modulation. While the watermarked image is tampered unauthorizedly, it compares the halftoned tampered image and the magnified extracted watermark to localize the tampered areas automatically without initial bi-watermark. Experimental results show that the proposed algorithm is effective for smaller area tamper localization and recovery.

Key words: semi-fragile digital watermark, multiwavelet, halftone, tampering recovery

中图分类号: 

• TP391