The computation of polygonal approximations for 2D contours based on a concavity tree

•A proposal to improve methods to obtain polygonal approximations is proposed.•The required levels of detail are achieved using the concavity tree.•The local Measurement ISE/CR is used as stop condition.•The proposed algorithm improves the methods tested. In this work, a new proposal to improve some methods based on the merge approach to obtain polygonal approximations in 2D contours is presented. These methods use a set of candidate dominant points (CDPs) to obtain a polygonal approximation. Then, redundant candidate dominant points of the set of CDPs are deleted, and the remaining dominant points will be the polygonal approximation of the original contour. The main drawback of most of these methods is that they use all breakpoints as CDPs and most of these breakpoints depict only the noise of the original contour. Our proposal, based on a concavity tree, obtains a more reduced and significant set of CDPs. When this proposal is used by some methods based on the merge approach (the Masood methods and the Carmona method), their computation times are reduced. The experimental results show that the new proposal is efficient and improves the tested methods.