Why not see how much you know about this topic already? Then work through the page and see if you can beat your score. Parallel lines are the same distance apart from each other all the way along ...

In this case the 2D Radon transform is sampled for , , and , . Here is the radius of the reconstruction region, i.e. we assume f(x) = 0 for , . This means that the measured rays come in p parallel ...