clear;
moon6dsmmat = imread('moon6dsm.jpg'); 
u = double(moon6dsmmat)
mesh(u);
[nx ny] = size(u)
c = 1.;
gamma = .5;
newu =255*c*(u/255).^gamma;
moon6dsm1 = uint8(newu);
imwrite(moon6dsm1, 'moon6dsm1.jpg');