clear?all;
img?=?imread（‘圖片2.png‘）;
img?=?rgb2gray（img）;
figure;imshow（img?[]）
[m?n]?=?size（img）;
img_hist?=?zeros（1256）;
for?i?=?1:m
????for?j?=?1:n
????????img_hist（img（i?j）+1）?=?img_hist（img（i?j）+1）?+?1;
????end
end
img_hist_pro?=?img_hist/m/n;?????????%灰度級概率密度分布
%?plot（img_hist_pro）
%?figure;imhist（img）
sigma2_max?=?0;threshold?=?0;
for?t?=?0:255
????w0?=?0;w1?=?0;?u0?=?0;?u1?=?0;?u?=?0;
????for?q?=?0:255
????????if?q?<=?t
????????????w0?=?w0?+?img_hist_pro（q+1）;
????????????u0?=?u0?+?（q）*img_hist_pro（q+1）;
????????else
????????????w1?=?w1?+?img_hist_pro（q+1）;
????????????u1?=?u1?+?（q）*img_hist_pro（q+1）;
????????end
????end
????u?=?u0?+?u1;
????u0?=?u0?/?（w0+eps）;
????u1?=?u1?/?（w1+eps）;
????sigma2?=?w0?*?（u0?-?u）^2?+?w1?*?（u1?-?u）^2;?????%求取類間最小
????if?（sigma2?>?sigma2_max）
????????sigma2_max?=?sigma2;
????????threshold?=?t;
????end
end
img_out?=?img;
for?i?=?1:m?????????????????????????????????????????%閾值化
????for?j?=?1:n
????????if?img（i?j）?>=?threshold;
????????????img_out（i?j）?=?255;
????????else?
????????????img_out（i?j）?=?0;
????????end
????end
end
figure;imshow（img_out）
????

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

?????文件???????1176??2013-01-10?21:17??作業4\adaptivethresh.m

?????文件???????1653??2013-01-10?21:27??作業4\adaptivethresh2.m

?????文件????1230242??2013-01-10?21:31??作業4\result.tif

?????文件?????146415??2013-01-09?20:39??作業4\圖片1.png

?????文件?????397940??2013-01-03?14:52??作業4\圖片2.png

?????文件??????22594??2013-01-10?22:05??作業4\自適應門限法將圖像二值化.docx

?????目錄??????????0??2013-01-11?18:49??作業4

-----------?---------??----------?-----??----

??????????????1800020????????????????????7