Low-complexity arrays of contour signatures for exact shape retrieval

We propose a framework for a fast exact shape retrieval called Low-complexity Arrays of Contour Sig-natures. The purposes are to match a shape against a database in constant time and to retrieve correct shapes very close to the query, while the latter may have undergone rigid transformations and noise. We present a shape signature based on prior works as well as a compact characterization of such signatures, a system of associative arrays allowing a short search time for retrieval and a technique of pairwise align-ment. This method shows a good resilience to perturbations and is performed in constant computational time. (c) 2021 Elsevier Ltd. All rights reserved.