f=imread（‘t.jpg‘）;
imwrite（f‘t.jpg‘）;
k=imfinfo（‘t.jpg‘）;
ib=k.Width*k.Height*k.BitDepth/8;
cb=k.FileSize;
cr=ib/cb;
disp（cr）;

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

?????文件????????316??2010-01-29?15:50??SNR.m

?????文件????????571??2010-01-26?15:05??wp.m

?????文件????????133??2010-01-29?14:50??Compression.m

?????文件???????1031??2010-01-14?16:27??wave.m

?????文件????????585??2010-01-16?17:28??thresholds.m

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

?????????????????2636????????????????????5