高级检索

    基于零系数索引的可逆图像水印

    Invertible Image Watermarking Based on Zero Coefficient Index

    • 摘要: 提出一种新的用于压缩图像的具有高容量和低失真特点的可逆水印算法,在提取水印后可还原原始的压缩图像.该算法使用量化DCT块的中高频零系数索引值进行水印嵌入和提取.只要候选系数范围内最大的零系数索引不小于水印的整数值,就可以通过修改一位零系数来嵌入多个比特的水印.由于降低了被修改系数与嵌入的水印位数比例,该算法能在引入较少失真的情况下嵌入大量的水印.实验结果表明相对于其他基于DCT压缩域的可逆图像水印算法,该算法在水印容量和嵌水印图像质量方面具有优势,并且具有良好的适应性和可调整性.

       

      Abstract: Invertible watermarking is a type of schemes which has the capability that recovers the host media without any loss after embedded data is extracted, and plays key roles in scenarios where exact host media are crucial. In practical applications, compressed images are widely used for easy storage and transfer. Proposed in this paper is a novel invertible watermarking method with high capacity and low distortion for compressed images, in which original compressed images can be exactly retrieved on the extracting side. A sequence of coefficients in the medium and high frequencies of a quantized DCT block is defined as the candidate position for embedding. As long as the maximum index of zero coefficients in this sequence is not smaller than the integer value of watermark bits, the proposed method can embed these bits by modifying only one zero coefficient. Since the ratio between the number of modified coefficients and the number of watermark bits is low, a large amount of watermark can be embedded with low distortion. Experimental results demonstrate that the capacity and quality of watermarked images of the proposed scheme are better than those of the schemes as reported in other state-of-the-art literature. In addition, the proposed scheme is also well adaptable and configurable.

       

    /

    返回文章
    返回