“…In this study, image enhancement techniques (Gonzalez and Woods, 2002) have been formulated as optimisation problems and solved by nature inspired optimisation algorithms. Genetic algorithm (GA), particle swarm optimisation (PSO), differential evolution (DE), Cuckoo search (CS), artificial bee colony (ABC), firefly algorithm (FA) are some nature inspired metaheuristic algorithms which were effectively used in image enhancement field Ghosh, 2009, 2011;Munteanu and Rosa, 2001;Pal et al, 1994;Hashemi et al, 2010;Coelho et al, 2009;Dhal et al, 2015aDhal et al, , 2015bDhal et al, , 2015cDhal et al, , 2015dDhal et al, , 2017bDhal et al, , 2017aShanmugavadivu et al, 2014;Braik et al, 2007;Quraishi et al, 2012;Das, 2016, 2015;Quraishi et al, 2013). PSO gave better results than GA in the image enhancement domain by maximising employed entropy-based objective function.…”