grayturn.m

将彩色图像灰度化

im1=imread(filename);
if isgray(im1)==0
    im1=rgb2gray(im1);
      end
f=im1;
im1=double(im1);
[m n]=size(im1);
for i=1:m
   i
   for j=1:n
if im1(i,j)<=60
   im2(i,j)=40;
elseif im1(i,j)>=200
   im2(i,j)=245;
else im2(i,j)=((245-40)/(200-60))*(im1(i,j)-60)+40;
   end
   end 
end
y=uint8(im2);
subplot(1,2,1);subimage(f);axis off;title('old');
subplot(1,2,2);subimage(y);axis off;title('new');