闭运算能很好得消除遥感图像中的椒盐噪声和空洞
expond =fltarr(num_cols,num_rows) for i=1,num_cols-2 do begin for j=1,num_rows-2 do begin if shadow(i-1,j-1)+shadow(i-1,j)+shadow(i-1,j+1)+$ shadow(i,j-1)+shadow(i,j+1)*$ shadow(i+1,j-1)+shadow(i+1,j)+shadow(i+1,j+1)gt 0 then begin expond(i,j) =1.00 endif endfor endfor expondfs =expond for i=1,num_cols-2 do begin for j=1,num_rows-2 do begin if expond(i-1,j-1)*expond(i-1,j)*expond(i-1,j+1)*$ expond(i,j-1)*expond(i,j+1)*$ expond(i+1,j-1)*expond(i+1,j)*expond(i+1,j+1)eq 0 then begin expondfs(i,j) =0.00 endif endfor endfor