【作者】 左言胜；

【导师】 柴晓冬；

【作者基本信息】 安徽大学 ， 信号与信息处理， 2007， 硕士

【摘要】 近年来，相位恢复算法己经成为一个很重要的研究领域，这主要是由于相位恢复算法在信号复原、设计光学衍射元件等方面有所应用。其中极具代表性的有GS算法、迭代傅里叶变换算法及YG算法。迄今为止，相位恢复算法研究的大部分工作都集中在如何提高收敛速率和精确度上。本文概述了研究相位恢复算法的意义、起源及发展状况；详细介绍了各种由光强反复迭代得到相位分布的方法和通过解光强分布传输方程得到相位分布的方法。由于GS算法常常陷于局部极小的困境，使计算进程陷入几乎完全停滞的状态，本文中提出了一种改进型的GS算法，利用中间结果及一个加权因子来切换初始条件，该算法能够方便而随机地切换初始相位从而达到在一定程度上克服上述缺点的目的，并进行了模拟试验，证明了该算法的可行性。另外，WEB服务是近年来发展的热点，它是一种崭新的信息交换手段，本文提出了一种基于相位恢复的WEB服务的解决方案，对WEB服务进行了简单的介绍，对于具体实现中的问题也进行了研究，并进行了模拟试验，证明了该方案的可行性。更多还原

【Abstract】 Recently, the phase retrieval algorithm has been a very important research field, mainly because of its application in signal recovery and designing diffractive optical elements. In that field, the GS algorithm, IFT algorithm and Y-G algorithm are very representative. So far, mainly jobs of phase retrieval algorithm research have focused on improving the convergence speed and the precision.In this paper, the author studied the significance, origins, and development of the phase retrieval algorithm, detailedly introduced all kinds of methods of obtaining the phase distribution by repeatedly iterates the light intensity and by solving the transmission equation of light intensity distribution. Usually GS algorithm falls into a statement of local minimum, which causes that the computation course falls into nearly completely stagnancy. Therefore, in this paper, an advanced version GS algorithm has been designed,which uses a parameter to create a weighted average of the intermediate calculated results and then gives a new initial phase condition. Therefore the initial phase condition can be switched quickly and randomly to overcome this disadvantage, and the simulation experiment proved the feasibility of the algorithm.In addition, the WEB service is a hotspot of the development recently, and it is a brand-new means of information exchange. In this paper, we proposed a solution of WEB service based on phase retrieval, and simply introduced the WEB service. The specific problems in realization were also studied. The simulation test was done so that we proved the feasibility of the algorithm.更多还原