function?d=db（IIn）
%%?計算信噪比?SNR?
%%?輸入?I為原始無噪聲信號?In?為噪聲信號
%%?snr=db（IIn）;

n=I-In;?%?計算噪聲
Ps?=?sum（sum（（I?-?mean（mean（I）））.^2））;?%?信號強度
Pn?=?sum（sum（n.^2））;?%?噪聲強度

d=10*log10（Ps/Pn）;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件??????66614??2008-03-28?10:29??NLMeans\barbara.bmp

?????文件??????17464??2008-06-14?16:49??NLMeans\barbara128.bmp

?????文件???????5176??2008-06-14?16:49??NLMeans\barbara64.bmp

?????文件??????66616??2008-03-29?18:05??NLMeans\bartexture.bmp

?????文件??????66616??2008-05-28?10:02??NLMeans\bridge.bmp

?????文件??????17464??2008-06-14?16:52??NLMeans\bridge128.bmp

?????文件???????5176??2008-06-14?16:52??NLMeans\bridge64.bmp

?????文件??????66616??2008-03-27?22:52??NLMeans\cameraman.bmp

?????文件????????229??2008-06-13?16:24??NLMeans\db.m

?????文件??????66616??2008-05-28?10:04??NLMeans\dog.bmp

?????文件???????2421??2008-04-21?16:10??NLMeans\filters.m

?????文件??????66616??2007-05-19?21:57??NLMeans\lena.bmp

?????文件??????17464??2008-06-12?11:58??NLMeans\lena128.bmp

?????文件???????5176??2008-06-12?11:59??NLMeans\lena64.bmp

?????文件??????66616??2007-06-15?20:29??NLMeans\manmade.bmp

?????文件??????17464??2008-06-14?16:51??NLMeans\manmade128.bmp

?????文件???????5176??2008-06-14?16:52??NLMeans\manmade64.bmp

?????文件???????2222??2008-06-15?16:25??NLMeans\NLmeans.m

?????文件??????66616??2008-03-28?10:27??NLMeans\peppers.bmp

?????文件??????17464??2008-06-14?16:50??NLMeans\peppers128.bmp

?????文件???????5176??2008-06-14?16:50??NLMeans\peppers64.bmp

?????文件????????649??2008-06-15?14:55??NLMeans\Psnr.m

?????文件????????481??2008-06-15?14:26??NLMeans\SNR.m

?????文件????????466??2008-06-15?15:46??NLMeans\start.asv

?????文件???????1652??2008-06-15?15:53??NLMeans\start.m

????..A.SH.????146944??2008-07-02?21:17??NLMeans\Thumbs.db

?????文件????????559??2007-10-03?22:04??NLMeans\weight.m

?????文件??????90936??2008-05-28?10:01??NLMeans\woman.bmp

?????文件??????89144??2008-05-28?10:11??NLMeans\zebra.bmp

?????文件??????23096??2008-06-14?16:51??NLMeans\zebra128.bmp

............此處省略5個文件信息