In dealing with optical imaging systems, it is more feasible experimentally to measure line spread functions than point spread functions. When the intensity distribution is known to possess rotational symmetry, the point spread function can be obtained mathematically from the corresponding line spread function by solving an integral equation. A direct solution of this equation is given which represents a procedure that is simpler for practical use than the usual one involving Fourier transforms.
E. W. MARCHAND, "Derivation of the Point Spread Function from the Line Spread Function," J. Opt. Soc. Am. 54, 915-919 (1964)