To solve the problem of watermark encryption , a novel permutation operator is proposed , based on which the permutation scheme and the substitution scheme for watermark encryption are designed ; encryption algorithms in spatial domain and transform domain are proposed . the ciphered image can be jpeg compressed before it is transmitted , and low - distortion plain image can be obtained after decrypting the compressed encryption image 为解决水印信息加密问题,我们在第三章提出混沌有序化算子方法,设计了水印信息加密的置乱模块和替代模块;还给出了空间域和变换域数字图像加密算法,密文图像可以经过有损压缩再传输,经过解密得到低失真的明文图像。
In the first part , the research progress of cloud motion wind was introduced and the significance of the 1 - d fourier analysis technique was given . in the second part , based on fluctuation theory and fourier analysis , the one dimension fourier analysis technique on cloud motion winds is deduced and demonstrated theoretically . by simulating mathematically on frequency and on space , we not only uncovered two questions in practice , first is phrase folding , second is frequency spectrum overlapping , but also gave methods and suggestions to solve them or avoid them 本文由六章组成，第一章介绍云导风技术的研究进展和傅立叶导风技术的研究意义；第二章以波动理论和傅立叶变换为基础，对傅立叶相位导风技术进行理论推证和误差分析，通过模拟分析了空间域和频率域的导风特点，揭示了在导风过程中出现的相位重叠和频谱混叠两种现象；第三章通过计算在空间域速度线性变化情况下频率域振幅权重平均速度(
Gradually people began to make use of it actively to measure some physical quantities , thus self - mixing interference technology was brought forth . when a coherent light is scattered by the rough surface , the scatted light forms a granular intensity distribution known as speckle . speckles are coherent superposition of the light scatted by the rough surface 相干光从光学粗糙表面散射时，结果在探测面上出现随机的颗粒状的强度分布，称为散斑，散斑是由粗糙表面上各面元的散射光波之间的干涉在空间域内形成的，所以散斑也是粗糙表面一些信息的携带者。
By simulating mathematically on frequency and on space , we can find the average speed of space field and the average speed of frequency field that is weighted by amplitude , and analyse their relation , and analyse the meaning of space speed variance x and frequency speed variance v . in the fourth part , how to ensure the height of cloud is introduced , and basing on the theory of wind field continuity , the height updating quality controlling is introduced . in the fifth part , the system of cloud wind is introduced , we tracked cloud - motion of consecutive satellite images with one - minute interval by the 1 - d fourier analysis technique and the two - dim fourier analysis technique and the fft analysis technique , and dispose them with quality controlling . in the sixth part , we summarized our research and put up with shortages of this article 模拟模块内各点的速度线性变化时，得到空间域平均速度以及频率域以振幅为权重的平均速度，分析了空间域平均速度和频率域以振幅为权重的平均速度的关系，并揭示空间域的平均速度的标准差_ x和频率域的振幅为权重的平均速度的标准差_ v的意义，以及它们之间的关系；第四章介绍了云迹风系统的高度指定以及风矢高度的划分，并根据风场连续性原理，介绍了高度调整法的质量控制；第五章介绍导风系统的流程，选择了三个时刻的ir云图，分别用一维傅立叶相位法、二维傅立叶相位法和快速傅立叶算法计算一个风场个例，并对所得风场进行质量控制，并给出风场图；第六章进行研究总结，指出不足和有待于进一步研究之处。
This thesis is about digital watermarking technology and applications research based on fingerprint data . the main distributions of this thesis are : a fingerprint image watermarking algorithm in time / spatial domain is studied : most of traditional watermarks are pseudo - random sequences or binary images , which are of less information and worse security 本文是关于基于指纹数据的水印技术及其应用的一些研究,主要做了以下工作:研究了一种将指纹灰度图像作为水印信息的时间/空间域水印算法:传统水印信息大都是一维id序列(伪随机序列)或二值图像,这种水印技术所包含的信息量少,保密性差。
