Increase in resolution with number of back projections

Matlab code 

% Movie showing improvement in image quality with the number of back

% projections

 

clear all; close all

vid = VideoWriter('backProjection.mp4','MPEG-4');

vid.Quality = 100;

vid.FrameRate = 10;

open(vid);

figure('units','pixels','position',[0 0 1920 1080],'ToolBar','none');

set(0,'defaultfigurecolor',[1 1 1]);

myIm = imread('cartoonFly.png');

 

for ii = 1:180

    sino = radon(myIm,0.0000001:180/ii:180); % First one bp only, then 2, 3, etc

    backproj = iradon(sino,0.0000001:180/ii:180);

    imshow(backproj);

    caxis([0 max(max(backproj))]);

    hold on

    axis square

    axis off

    colormap(gray)

    str1 = '# back projections = ';

    str2 = num2str(ii,'% 3i');

    strTot = [str1,str2];

    annotation('textbox',[0.32 0.14 0.14 0.07],'String',strTot,'EdgeColor',...

        'none','FontSize',11,'FitBoxToText','on','HorizontalAlignment',...

        'left','verticalAlignment','bottom','Color','w');

    frame = getframe(gcf);

    writeVideo(vid,frame);

    if (ii<=10)

        pauseMov(vid,9);

    elseif (ii>10) && (ii<=20)

        pauseMov(vid,4);

    end

    hold off

    delete(findall(gcf,'type','annotation'));

end

% Output the movie as an mpg file

close(vid);