目录摘要....................................................................................................................................3Abstract........................................................................................................................4第一章绪论......................................................................................................................51.1研究目的和意义..................................................................................................51.2图像去噪的研究历史..........................................................................................51.3小波国内发展......................................................................................................61.4小波国外发展......................................................................................................61.5本文结构组成......................................................................................................7第二章小波变换基本理论..............................................................................................82.1小波分析理论......................................................................................................82.2傅里叶变换和小波变换......................................................................................82.3小波变换在图像去噪中应用..............................................................................8第三章小波变换阈值去噪............................................................................................123.1常用小波基函数................................................................................................123.1.1Haar小波................................................................................................123.1.2dbN小波..................................................................................................133.1.3symN小波...............................................................................................153.1.4三种小波基函数比较框图......................................................................163.2阈值选取............................................................................................................173.2.1Visushrink阈值......................................................................................173.2.2Bayesshrink阈值....................................................................................173.3常用阈值函数....................................................................................................173.3.1硬阈值函数（hardthresholding）.......................................................173.3.2软阈值函数（softthresholding）.........................................................17第四章仿真实验结果与分析........................................................................................194.1噪声....................................................................................................................194.2图像去噪效果性能指标....................................................................................194.3图像去噪算法仿真实验....................................................................................194.3.1小波分解..................................................................................................204.3.2图像去噪结果..............
