function?[mssim?ssim_map]?=?ssim（img1?img2?K?window?L）
%UNtitleD?Summary?of?this?function?goes?here
%???Detailed?explanation?goes?here

%
%Input?:?（1）?img1:?the?first?image?being?compared
%????????（2）?img2:?the?second?image?being?compared
%????????（3）?K:?constants?in?the?SSIM?index?formula?（see?the?above
%????????????reference）.?defualt?value:?K?=?[0.01?0.03]
%????????（4）?window:?local?window?for?statistics?（see?the?above
%????????????reference）.?default?widnow?is?Gaussian?given?by
%????????????window?=?fspecial（‘gaussian‘?11?1.5）;
%????????（5）?L:?dynamic?range?of?the?images.?default:?L?=?255
%
%Output:?（1）?mssim:?the?mean?SSIM?index?value?between?2?images.
%????????????If?one?of?the?images?being?compared?is?regarded?as
%????????????perfect?quality?then?mssim?can?be?considered?as?the
%????????????quality?measure?of?the?other?image.
%????????????If?img1?=?img2?then?mssim?=?1.
%????????（2）?ssim_map:?the?SSIM?index?map?of?the?test?image.?The?map
%????????????has?a?smaller?size?than?the?input?images.?The?actual?size
%????????????depends?on?the?window?size?and?the?downsampling?factor.
%
%??sic?Usage:
%???Given?2?test?images?img1?and?img2?whose?dynamic?range?is?0-255
%
%???[mssim?ssim_map]?=?ssim（img1?img2）;
%
%??vanced?Usage:
%???User?defined?parameters.?For?example
%
%???K?=?[0.05?0.05];
%???window?=?ones（8）;
%???L?=?100;
%???[mssim?ssim_map]?=?ssim（img1?img2?K?window?L）;
%
%Visualize?the?results:
%
%???mssim????????????????????????%Gives?the?mssim?value
%???imshow（max（0?ssim_map）.^4）??%Shows?the?SSIM?index?map
%========================================================================

if?（nargin??5）
???ssim_index?=?-Inf;
???ssim_map?=?-Inf;
???return;
end
if?（size（img1）?~=?size（img2））
???ssim_index?=?-Inf;
???ssim_map?=?-Inf;
???return;
end
[M?N]?=?size（img1）;
if?（nargin?==?2）
???if?（（M?????ssim_index?=?-Inf;
????ssim_map?=?-Inf;
??????return
???end
???window?=?fspecial（‘gaussian‘?11?1.5）;?%
???K（1）?=?0.01;?????%?default?settings
???K（2）?=?0.03;?????%
???L?=?255;?????????????????????????????????????%
end
if?（nargin?==?3）
???if?（（M?????ssim_index?=?-Inf;
????ssim_map?=?-Inf;
??????return
???end
???window?=?fspecial（‘gaussian‘?11?1.5）;
???L?=?255;
???if?（length（K）?==?2）
??????if?（K（1）??????ssim_index?=?-Inf;
?????ssim_map?=?-Inf;
?????return;
??????end
???else
????ssim_index?=?-Inf;
????ssim_map?=?-Inf;
????return;
???end
end
if?（nargin?==?4）
???[H?W]?=?size（window）;
???if?（（H*W）??M）?|?（W?>?N））
????ssim_index?=?-Inf;
????ssim_map?=?-Inf;
??????return
???end
???L?=?255;
???if?（length（K）?==?2）
??????if?（K（1）??????ssim_index?=?-Inf;
?????ssim_map?=?-Inf;
?????return;
??????end
???else
????ssim_index?=?-Inf;
????ssim_map?=?-Inf;
????return;
???end
end
if?（nargin?==?5）
???[H?W]?=?size（window）;
???if?（（H*W）??M）?|?（W?>?N））
????ssim_

?屬性????????????大小?????日期????時間???名稱
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????I.A....??????4683??2013-10-14?09:17??ssim.m

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?????????????????4683????????????????????1