function [ct] = CTs(I,start,increment,num,method,fltr)

if(I==0)
I = buildImage(0);
else
I = I(1:4:size(I,1),1:4:size(I,2));
end

imagesc(I);colormap(gray);
pause



[rays,phis] = extractRays(I,start,increment,num);

if(method==0)
  ct = backProject(rays,phis,size(I),fltr);
elseif(method==1)
  ct = backSplash(rays,size(I),phis,fltr);
end

figure(2)
imagesc(ct);colormap(gray);