function e=qiege(d) [m,n]=size(d); top=1; bottom=m; left=1; right=n; while sum(d(top,:))==0&⊤1 bottom=bottom-1; end while sum(d(:,left))==0&&left;=1 right=right-1; end dd=right-left; hh=bottom-top; e=imcrop(d,[left top dd hh]);