目錄

摘要

Abstract
第一章 引言...........................................................................................................1
1．1研究的目的和意義...................................................................................1
1．2國(guó)內(nèi)外研究現(xiàn)狀.......................................................................................1
1．3研究的內(nèi)容...............................................................................................3
第二章 斑點(diǎn)噪聲的形成原理與斑點(diǎn)噪聲模型...................................................4
2．1斑點(diǎn)噪聲的形成原理...............................................................................4
2．2斑點(diǎn)噪聲的特征.......................................................................................5
2．2．1斑點(diǎn)噪聲的概率分布函數(shù).............................................................5
2．2．2斑點(diǎn)噪聲的自相關(guān)函數(shù).................................................................5
2．2．3斑點(diǎn)噪聲的功率密度譜.................................................................5
2．3斑點(diǎn)噪聲模型...........................................................................................6
2．3．1 Rayleigh斑點(diǎn)噪聲模型..................................................................6
2．3．2乘性噪聲模型.................................................................................6
第三章 濾波方法發(fā)展的回顧...............................................................................9
3．1空間域的濾波方法...................................................................................9
3．1．1傳統(tǒng)方法.........................................................................................9
3．1．2局域統(tǒng)計(jì)自適應(yīng)濾波.....................................................................9
3．2頻率域的濾波方法.......................................................................................12
3．2．1Fourier變換方法................................................................................12
3．2．2基于小波分析的方法.........................................................................12
第四章 基于小波分析的SAR影像去噪的原理和方法......................................16
4．1小波變換及其特性.....................................................................................16
4．1．1小波變換........................................................................................16
4．1．2多尺度分析與正交小波變換........................................................17
4．1．3雙正交小波變換..........................................................................19
4．2隨機(jī)噪聲的小波變換特性......................................................................20
4．1．1模極大值與信號(hào)奇異度和尺度的關(guān)系....................................20
4．1．2模極大值傳播特性....................................................................21
4．3小波基的選擇..........................................................................................21
4．4應(yīng)用多尺度小波變換進(jìn)行SAR影像去噪.............................................22
4．4．1小波分解變換...........................................................................23
4．4．2小波多尺度去噪.......................................................................24
4．4．3小波逆變換重構(gòu)原圖像...........................................................25
第五章 濾波器性能評(píng)價(jià).....................................................................................26
5．1評(píng)價(jià)的基本思想............................................................................................26
5．2評(píng)價(jià)的方法和標(biāo)準(zhǔn).......................................................................................26
5．2．1斑點(diǎn)噪聲的濾除能力......................................................................26
5．2．2邊緣的保持能力.............................................................................26
5．3濾波器性能的評(píng)價(jià) ......................................................................................26
5．3．1影像的比較......................................................................................27
5．3．1．1條帶、點(diǎn)目標(biāo)和隨機(jī)噪聲模擬的SAR影像的比較.......27
5．3．1．2 Radarsat影像的比較........................................................30
5．3．2濾波器性能的定量評(píng)價(jià)..................................................................32
5．3．2．1均值的保留能力.................................................................32
5．3．2．2噪聲的濾除能力................................................................33
5．3．2．3邊緣的保持能力................................................................34
5．3．2．4線和點(diǎn)目標(biāo)的保持能力....................................................35
5．3．2．5自然的目視效果...................