clear;
n = 2.4;
m = 1.4;
img = imread('cameraman.tif');
[x,y] = meshgrid(1:size(img,2),1:size(img,1));
[x_new,y_new] = meshgrid(linspace(1,size(img,2),ceil(m*size(img,2)))...
                        ,linspace(1,size(img,1),ceil(n*size(img,1))));
img2 = interp2(x,y,double(img),x_new,y_new);
imshow(uint8(img2))