function [MDm]=sorteddist(imgaa,imgbb,m)
img1=double(imread(imgaa,'bmp'));
img2=double(imread(imgbb,'bmp'));
[sizex sizey K]=size(img1);
x=max(abs(img1-img2));
y=sort(x);
%MD1=(1./K)*(y(1,sizex,1)+y(1,sizex,2)+y(1,sizex,3))
delm=0;
for i=1:m
	delm=delm+y(1,sizex-i+1,1)+y(1,sizex-i+1,2)+y(1,sizex-i+1,3);
end

MDm=(delm./m)./K