用于彩信业务版权保护的图像水印

Robust Image Watermarking Scheme and Its Application in MMS

为了解决目前彩信业务中移动数字内容的版权保护、使用控制及计费管理,提出了基于数字水印的版权保护与管理系统方案WDRM(watermarkbaseddigitalrightsmanagement)。设计了一种鲁棒的数字图像水印算法,以两个独立的水印,分别代表图片提供商信息和网络运营商信息;以待嵌入的信息为种子,产生具有良好自相关特性的随机序列作为水印信号,并根据人类视觉系统HVS(humanvisionsystem)的特性,对原始图像块进行分类,根据分类的结果将水印信号以不同的强度嵌入到图像块的DCT中频系数上;通过计算相关值来提取水印。实验结果表明,该水印算法能抵抗典型的图像处理,如加噪、滤波、压缩、增删线条或字等,基本满足当前彩信业务的要求。

Watermark based digital rights management (WDRM) system is proposed to protect the copyright of mobile digital contents and solve the problem of interest distribution between network operators and content providers in MMS (Multimedia Messaging Service). A robust image watermark scheme is developed. Two independent watermarks are embedded which represent the messages of content providers and network operators repectively. The original image is segmented into 8×8 blocks and the watermarks are embedded by modifying the mid_band DCT coefficients of the image blocks with different strengths according to the characteristics of Human Vision System(HVS). This scheme gets a good balance between the invisibility and robustness. The experimental results demonstrate that the embedded watermark is robust against many common images processing such as noising, filtering, compression and adding words or lines.