%timing study
clear all; close all;
a = im2double(imread('barb.tif'));
imshow(a)
tic
b = sqrt(a);
toc
pause
figure, imshow(b)
tic
for i = 1:512
    for j = 1:512
        c(i,j) = sqrt(a(i,j));
    end
end
toc
pause
figure, imshow(c)