This is code for The Filtered Backprojection Algorithm(FBP), which is the result for 'radon' and 'iradon' about three images. Image1(FBP1) is a matrix, , image2(FBP2) is a CT of head, image3(FBP3) is a CT of kidney. We can see that for more complex image, more 'beam' needed for FBP.
