I have a PSF code and I need to generate the MTF and plot it along with the spatial frequency graph, similar to the image attached. I would greatly appreciate your assistance

% Imaging with Zone Plate

for tt=1:1

z2 = s2+s2/5000*tt;

h2 = exp(1i*2*pi*z2*sqrt(1/(lambda)^2-(x/L).^2-(y/L).^2));

E2 = ifft2(fftshift(fftshift(fft2(E.*exp(1i*FZP))).*h2));

psf=fftshift(fft2(exp(1i*FZP)));

resulting_image = abs(E2).^2;

figure(200+tt)

imagesc(abs(E2).^2);

title('resulting_image')

axis square;

I need assistance in calculating MTFfrom PSF, plotting MTF vs spatial frequency graph, and calculating the Strehl ratio. I am a beginner and have been struggling with this for a long time. Your help would be greatly appreciated.