function?AVEGRAD=avegrad（img）
%%%%?this?function?is?used?to?calculate?theaverage?gradient?of?an?image.
%%%%平均梯度可敏感地反映圖像對微小細節反差表達的能力，可用來評價圖像的模糊程度
%%%%在圖像中，某一方向的灰度級變化率大，它的梯度也就大。因此，可以用平均梯度值來衡量圖像的清晰度，還同時反映出圖像中微小細節反差和紋理變換特征。
img=double（img）;
[MN]=size（img）;
gradval=zeros（MN）;?%%%?save?the?gradient?value?of?single?pixel
diffX=zeros（MN）;?%%%?save?the?differential?value?of?X?orient
diffY=zeros（MN）;?%%%?save?the?differential?value?of?Y?orient
tempX=zeros（MN）;
tempY=zeros（MN）;
tempX（1:M1:（N-1））=img（1:M2:N）;
tempY（1:（M-1）1:N）=img（2:M1:N）;
diffX=tempX-img;
diffY=tempY-img;
diffX（1:MN）=0;?%%%?the?boundery?set?to?0
diffY（M1:N）=0;
diffX=diffX.*diffX;
diffY=diffY.*diffY;
AVEGRAD=（diffX+diffY）/2;
AVEGRAD=sum（sum（sqrt（AVEGRAD）））;
AVEGRAD=AVEGRAD/（（M-1）*（N-1））;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件?????????896??2014-08-28?17:19??Contourlet\avegrad.m
?????文件?????????485??2009-10-02?10:10??Contourlet\avg_gradient.m
?????文件????????1119??2012-10-24?17:03??Contourlet\backsamp.m
?????文件?????????778??2012-10-24?16:19??Contourlet\brenner.m
?????文件????????2309??2012-10-24?17:03??Contourlet\ChangeLog
?????文件???????22199??2009-02-14?21:52??Contourlet\clockA.jpg
?????文件???????19882??2009-02-14?21:52??Contourlet\clockB.jpg
?????文件????????4967??2012-10-24?17:03??Contourlet\computescale.m
?????文件????????3457??2012-10-24?17:03??Contourlet\Contents.m
?????文件?????????691??2012-10-24?17:03??Contourlet\COPYING
?????文件????????3391??2012-10-24?17:03??Contourlet\decdemo.m
?????文件????????2390??2012-10-24?17:03??Contourlet\denoisedemo.m
?????文件????????2223??2012-10-24?17:03??Contourlet\dfbdec.m
?????文件????????1700??2012-10-24?17:03??Contourlet\dfbdec_l.m
?????文件????????1667??2012-10-24?17:03??Contourlet\dfbimage.m
?????文件????????2012??2012-10-24?17:03??Contourlet\dfbrec.m
?????文件????????1736??2012-10-24?17:03??Contourlet\dfbrec_l.m
?????文件????????2729??2012-10-24?17:03??Contourlet\dfilters.m
?????文件?????????755??2012-10-24?17:03??Contourlet\dup.m
?????文件????????1356??2009-06-26?12:47??Contourlet\edge_association.m
?????文件????????1103??2012-10-24?17:03??Contourlet\efilter2.m
?????文件?????????813??2009-06-26?12:48??Contourlet\entropy_fusion.m
?????文件????????1861??2012-10-24?17:03??Contourlet\extend2.m
?????文件????????2098??2012-10-24?17:03??Contourlet\fbdec.m
?????文件????????1507??2012-10-24?17:03??Contourlet\fbdec_l.m
?????文件????????2360??2012-10-24?17:03??Contourlet\fbrec.m
?????文件????????1426??2012-10-24?17:03??Contourlet\fbrec_l.m
?????文件?????????485??2012-10-24?17:03??Contourlet\ffilters.m
?????文件?????????996??2007-08-20?23:27??Contourlet\Hab.m
?????文件????????3240??2013-01-18?10:03??Contourlet\KSVDOMP3.m
?????文件?????????856??2012-10-24?17:03??Contourlet\ld2quin.m
............此處省略126個文件信息