结合B样条小波的半脆弱水印

A Semi-fragile Digital Watermarking Scheme Based on B-spline Wavelet

根据两条B样条曲线低分辨表示部分的大小关系在JPEG压缩下较稳定的特点提出了一种用于图像认证的半脆弱数字水印方法。产生一个依赖于原图像内容的水印,将图像进行8×8分块,并分为两组,在每一组中分别取一个分块,选择特定点的像素值作为控制顶点,构造B样条曲线,对B样条进行多分辨分解,通过修改两条B样条曲线低分辨表示部分的大小关系嵌入水印。该算法可以检测并定位被修改的位置,可用于图像的完整性认证,并有一定的抗压缩能力。

A semi-fragile watermarking for image authentication which based on the factor that the spatial relationship between couple low-resolution of B-spline withstands JPEG compression is proposed. Firstly, a content-based watermark is created from the original image. All 8×8 blocks are divided into two sets, two couples B-spline are defined in each couple block. Then these B-spline curves are decomposed. The bits of watermark are embedded by modifying the relationship between couple B-splines＇ low-resolution coefficients. The algorithm can detect and locate the tamper of the image. It can be used for integrity authentication.