I_rgb=imread('lena.jpg');%subplot(2,2,1),imshow(I_rgb),title('lena-rgb')I_gray=rgb2gray(I_rgb);%subplot(2,2,2),imshow(I_gray),title('lena-gray')I=imresize(I_gray,0.25);%subplot(2,2,3),imshow(I),title('lena-qtr')fid=fopen('./lena.txt','wt');