Abstract: Concerning the shortage of the tamper localization accuracy and tamper recovery performance in the existing image tampers localization and recovery algorithms, the authors proposed a precise three-watermarking algorithm. It generated three types of watermarks such as detection watermark, localization watermark and recovery watermark by binary coding based on Least Significant Bit (LSB). The watermarks were imbedded into the low bits of image. Tamper detection and recovery were implemented by detection watermark and recovery watermark based on blocks, and precise localization was implemented by localization watermark based on single pixel. The simulation results show that the proposed algorithm has precise tamper localization to any size of brightness images and RGB images, and has good tamper recovery performance.

Key words: three-watermark algorithm, tamper detection, tamper localization, tamper recovery, binary coding

摘要： 针对目前图像篡改定位与恢复的水印算法在篡改定位精度和篡改恢复性能方面存在的不足，提出一种精确的图像篡改定位与恢复的三水印算法。该算法在最低有效位(LSB)方法的基础上，采用二进制编码的方式生成检测水印、定位水印和恢复水印等三种水印，并嵌入到图像的低位。篡改检测和篡改恢复采用基于分块的检测水印和恢复水印，篡改精确定位采用基于单像素的定位水印。仿真实验表明，该算法对任意大小的亮度图像、RGB图像具有高精度的篡改定位能力，并且具有很好的篡改恢复性能。

关键词: 三水印算法, 篡改检测, 篡改定位, 篡改恢复, 二进制编码