clc;
clear all;
for i=1:40
for j=1:10
image=imread(strcat(‘N:\FACE\orl_faces\s‘,...
int2str(i),‘\‘,int2str(j),‘.pgm‘));
imwrite(image,strcat(‘N:\FACE\orl_faces\s‘,...
int2str(i),‘\‘,int2str(j),‘.jpg‘));
end
disp(strcat(‘s‘,int2str(i),‘转换结束.‘));
end
disp(‘批量转换结束.‘);
原文：http://www.cnblogs.com/ahuo/p/4921267.html