function?[img_denoise]?=?Butterwirth（img_noisew1）
%?w1?截止頻率
n1=2;%2階巴特沃斯（Butterworth）低通濾波器
f=im2double（img_noise）;
g=fft2（f）;%傅立葉變換
g=fftshift（g）;%轉(zhuǎn)換數(shù)據(jù)矩陣
[MN]=size（g）;
m=fix（M/2）;
n=fix（N/2）;
for?i=1:M
???for?j=1:N
????????d=sqrt（（i-m）^2+（j-n）^2）;
????????h1=1/（1+0.414*（d/w1）^（2*n1））;%計算低通濾波器傳遞函數(shù)
????????s1（ij）=h1*g（ij）;
???end
end
y1=im2uint8（real（ifft2（ifftshift（s1））））;
img_denoise=y1;
end

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件??????185727??2005-09-11?15:43??barbara.png
?????文件??????261306??2016-06-15?14:23??barbara_gaussian.png
?????文件??????212184??2016-06-15?14:23??barbara_salt-pepper.png
?????文件??????251565??2016-06-15?14:23??barbara_speckle.png
?????文件?????????456??2020-06-20?21:20??Butterwirth.m
?????文件?????????298??2020-06-20?16:12??DCT.m
?????文件?????????648??2020-06-20?23:05??gauss.m
?????文件??????151199??2005-09-11?15:44??lena.png
?????文件??????261301??2016-06-15?14:23??lena_gaussian.png
?????文件??????191951??2016-06-15?14:23??lena_salt-pepper.png
?????文件??????252508??2016-06-15?14:23??lena_speckle.png
?????文件????????6410??2020-06-21?14:11??main_denoise_1.m
?????文件????????7940??2020-06-21?14:39??main_denoise_2.m
?????文件????????3326??2020-06-21?16:56??main_denoise_3.m
?????文件????????8048??2020-06-21?19:14??main_denoise_4.m
?????文件????????3293??2020-06-21?20:06??main_denoise_5.m
?????文件?????????406??2020-06-20?19:56??mean_filter.m
?????文件?????????413??2020-06-20?20:13??median_filter.m
?????文件?????????949??2020-06-20?23:38??pc_a.m
?????文件???????40181??2002-08-29?17:48??peppers256.png
?????文件???????65430??2016-06-15?14:23??peppers256_gaussian.png
?????文件???????49606??2016-06-15?14:23??peppers256_salt-pepper.png
?????文件???????63082??2016-06-15?14:23??peppers256_speckle.png
?????文件?????????268??2020-06-20?17:20??psnr.m
?????文件?????????451??2020-06-21?19:08??wavedec_2.m