01193nas a2200145   4500008004100000020001400041245008500055210006900140260002300209300001600232490000700248520064700255100002000902856012500922       2007                        eng d  a0262-885600aA decomposition technique for reconstructing discrete sets from four projections0 adecomposition technique for reconstructing discrete sets from fo  bElseviercOct 2007  a1609 - 16190 v253 a<p>The reconstruction of discrete sets from four projections is in general an NP-hard problem. In this paper we study the class of decomposable discrete sets and give an efficient reconstruction algorithm for this class using four projections. It is also shown that an arbitrary discrete set which is Q-convex along the horizontal and vertical directions and consists of several components is decomposable. As a consequence of decomposability we get that in a subclass of <em>hv</em>-convex discrete sets the reconstruction from four projections can also be solved in polynomial time. Possible extensions of our method are also discussed.</p>1 aBalázs, Péter  uhttps://www.inf.u-szeged.hu/publication/a-decomposition-technique-for-reconstructing-discrete-sets-from-four-projections