提出一种基于小波变换的复合式数字栅格地图水印算法。其基本思想是在数字栅格地图的不同频域块中分别嵌入抗差性数字水印和脆弱性数字水印。基于数字栅格地图相比一般影像数据具有较高亮度,低频分量具有更高感觉容量的特点,在地图的小波低频域上自适应嵌入抗差性数字水印,以实现地图版权保护功能;结合人类视觉系统特性,利用抖动调制技术在小波高频域中嵌入脆弱性数字水印,以实现地图内容完整性认证功能。试验结果表明,该算法能对地图内容的完整性进行认证,同时对常见的各种攻击诸如JPEG压缩、锐化、剪裁等具有良好的抗差性。 更多还原
【Abstract】 A compound watermarking algorithm for digital raster map is proposed based on wavelet transformation.The basic idea is to embed the robust watermark and the fragile watermark into different frequency blocks of the digital raster map based on the features of digital raster map with higher luminance and greater sensual capability than image data.The robust watermark is adaptively embedded into low frequency section to protect the copyright of the data.The fragile watermark is embedded into high fr... 更多还原