Based on characteristics of human visual system ( hvs ) , including texture / contract masking property and sensitivity of frequency , and combining with wavelet multi - resolution theory , a novel just noticeable difference ( jnd ) model that can embed watermark adaptively is proposed 用该模型可使指纹特征信息生成的数字水印自适应嵌入合成的指纹图像中，提高了指纹认证系统的可信度。
With the development of war , the requirement on information processing techniques for precision guidance is becoming higher and higher . atr has become very important , this technique imitate human visual system 随着现代战争的发展，对精确制导信息处理技术的要求越来越高， atr (自动目标识别)技术已成为精确制导技术发展的方向，而atr技术的发展则是起源于人类对生物视觉的模仿。
In spatial domain , according to the characteristics of hvs ( human visual system ) , we introduce several approachs based on images " deviation , images " flatness measurement , fuzzy classification , and an approach based on difference matrix as well 在空间域内，利用人的视觉特性，我们提出了基于图象方差、图象平坦测度、模糊分类的隐藏算法，同时提出了基于差值矩阵的信息隐藏。
The wavelet transformation can provide a good mechanism to explore human visual system , while it removes the data correlation in image . so the image compression coding algorithm based on wavelet transformation has became researching hotspot in recent years 小波变换不仅可以去除图像数据中的相关,而且它提供了利用人眼视觉特性的良好机制,因此基于小波变换的图像压缩技术己成为当前的研究热点。
This paper employed the characteristics of the hvs ( human visual system ) responded to the image contents and realized the two kinds of image - adaptive watermark algorithm , one is in the spatial domain based on the statistics theory and another in the dct domain with meaningful digital watermark 本文利用hvs人类视觉系统模型，提出了图像内容自适应的数字水印算法，分别实现了时空域中的统计原理水印算法和dct变换域中的有意义水印算法。
Utilizing the characteristics of the human visual system , we embed a digital signal into the average value of the four adjacent wavelet coefficients since the average value has better stability than single wavelet coefficient . this method need n ' t original image when the watermark is extracting . experiment results show the effectiveness of this method which is robust to common image process and fragile to malicious attack , i . e . this method can detect the tampered portions 因此，本文利用小波系数均值来嵌入水印，提出了一种基于小波域的图像完整性验证的半脆弱水印算法，在鲁棒性和脆弱性方面达到了很好的平衡，对非恶意攻击有很强的鲁棒性，而对于恶意的篡改操作有很强的识别和定位能力。
( 3 ) the theories of human visual system and the human visual basic characteristics are introduced into the field of dynamic range extending , in order to give the direction of the image processing . the subjective and objective image quality assessment ways are also analyzed and synthesized ( 3 )研究了人眼视觉系统( hvs )和视觉基本特性等理论对扩展数字图像动态范围的指导性作用，并在目前并没有定论的图像质量评价方面，总结和分析了目前国内外的各种主观和客观评价系统。
Experiments prove that this algorithm not only give attention to the intensity of embedding watermarking but also guarantee the quality of image combining with human visual system better , and it has good robust and is available for information copyright protection for keeping meaningful watermarking intact under image processing attacks such as common noises , mean filter , sub - sample and jpeg compression etc 试验结果证明，本算法兼顾了嵌入水印强度的同时更好的保证了图像质量，不仅能很好的结合人眼视觉系统，且对一般的图像处理如抗噪声、均值滤波、亚抽样和jpeg压缩，都具有较好的鲁棒性，对水印特征信息具有有效的保护。
Digital image watermark , as a branch of data hiding technology , imbeds symbol information into the protected image using the redundancy attribute of human visual system . as a new methodology of copyright protection of digital image , it has become a hotspot in that field recently 数字图像水印技术是信息隐藏的一个分支，它利用人眼视觉冗余，将标志信息作为水印嵌入到被保护图像之中，是数字图像版权保护的一个新兴方法，也是数字产品版权保护领域中的一个研究热点。
Since watermark is added to visually more important regions of host image according to human visual system , and a pseudo - random permutation is performed in the wavelet domain before the watermark is embedded , which disperse the spatial relationship of pattern . therefore , even if the shape or the major location of the watermark is estimated , it ' s extremely difficult to detect or destroy the watermark with the cipher of permutation unknown 由于利用人眼视觉系统把数字水印嵌入到图像视觉较重要区域中，并且水印在嵌入前进行了小波域上的伪随机置乱，打乱了水印的空间关系，因此在置乱密钥未知的情况下，即使能估计出水印的形状和嵌入的主要位置，对水印的检测和破坏也是非常困难的。
