论文标题:基于小波提升的数字水印算法的研究
Research of Digital Image Watermarking Based on Wavelet Lifting Scheme
论文作者 杨润伟
论文导师 李晓,论文学位 硕士,论文专业 通信与信息系统
论文单位 新疆大学,点击次数 87,论文页数 58页File Size811k
2005-05-01论文网 http://www.lw23.com/lunwen_233591032/ 数字水印;JPEG2000;小波提升;置乱;均值量化
digital watermarking ; JPEG2000 ; wavelet lifting scheme ; scrambl ; means-quantization
随着信息技术的发展,单纯依靠传统密码学理论进行信息的安全防范已经不能满足社会的需要。用正常的多媒体文件(如图像、视频、音频等)作为掩护,隐藏秘密文件进行信息的传递成为一个重要的发展方向。相对于版权保护的水印技术,它是一个要求盲提取、大容量和良好不可感知性的信息隐藏技术。鉴于目前在图像压缩领域,JPEG2000 有着广泛的应用前景,本文提出一种基于JPEG2000 标准的图像数字水印技术。论文分析了JPEG2000 标准下小波提升的特点及置乱预处理对图像小波域系数的影响,根据分析结果提出了水印嵌入算法。本算法结合小波提升和人眼视觉系统(HVS)特点,通过对原始图像置乱预处理,改变其小波域能量分布,然后将水印数据以均值量化的方式嵌入到其低频子带。该方法同时兼顾了水印不可感知性和鲁棒性的需求,并有较大的数据容量。在此基础上,文章进一步改进嵌入策略,扩大水印嵌入范围,提高载体的数据容量,使数据嵌入量在一定攻击条件下达到一个令人满意的程度。仿真结果表明,算法具有较大的数据容量和不可感知性,具有一定的抵御攻击能力,实现了预期目标。同时该算法是基于JPEG2000 标准提出,随着JPEG2000 压缩格式的应用具有较好的应用价值。
With the development of information technology, the simple safe precaution that relied onthe traditional cryptography theory to carry on information can"t already meet demands ofsociety . Shield by the normal multimedia files (such as image , video , audio), the transmissionhiding the secret file and carrying on information becomes an important developing direction.The technology of watermark relative to copyright protection, it is an information hiddentechnology that demanded blindly drawn, large capacity and good imperceptibility. Seeingthat image compress field at present, JPEG2000 have an extensive application prospect, this textpropose one image digital watermark technology based on JPEG2000 standard.Thesis analyses characteristic of Wavelet Lifting Scheme and the putting haphazardpretreatment impacts on image DWT coefficient under JPEG2000 standard, according to theanalysis results, have proposed the watermark embedded algorithm. This algorithm combines theWavelet Lifting Scheme and characteristic of human eye vision system (HVS ), through puttingthe haphazard pretreatment to the primitive figure, changes its DWT energy distribution , thenembeds watermark data by means-quantization to its low frequency affiliated terrain. Thismethod has the watermark demands of intangiblity and robustness at the same time , and has thecapacity of larger data. On this foundation, the article improves the embedded tactics further,expands embedded range of watermark, improves the data capacity of carrier , makes theembedded amount of the data reach a satisfied degree under attacking condition.The artificialresult indicates , the algorithm has a large data capacity and intangibility, can resist the attackthat has no intention , has realized the re-set target. At the same time the Algorithm is proposedbased on JPEG2000 standard, with the application of JPEG2000 compression form ,it has abetter applied cost.
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