function plotIandIhat(I)
sizeI = size(I);
NX = sizeI(1);
NY = sizeI(2);
imagesc(-NX/2+1:NX/2, -NY/2+1:NY/2, I); 
xlabel('X');
ylabel('Y');
colormap gray; axis square;
figure;
imagesc( -NX/2+1:NX/2, -NY/2+1:NY/2, fftshift(log(abs(fft2(I)))));
xlabel('KX');
ylabel('KY');
colormap gray; axis square;