@article{10902/34576, year = {2021}, month = {1}, url = {https://hdl.handle.net/10902/34576}, abstract = {This work is an extension of a previous paper (presented at the Cyberworlds 2019 conference) introducing a new method for fractal compression of bitmap binary images. That work is now extended and enhanced through three new valuable features: (1) the bat algorithm is replaced by an improved version based on optimal forage strategy (OFS) and random disturbance strategy (RDS); (2) the inclusion of new similarity metrics; and (3) the consideration of a variable number of contractive maps, whose value can change dynamically over the population and over the iterations. The first feature improves the search capability of the method, the second one improves the reconstruction accuracy, and the third one computes the optimal number of contractive maps automatically. This new scheme is applied to a benchmark of two binary fractal images exhibiting a complex and irregular fractal shape. The graphical and numerical results show that the method performs very well, being able to reconstruct the input images with high accuracy. It also computes the optimal number of contractive maps in a fully automatic way. A comparative work with other alternative methods described in the literature is also carried out. It shows that the presented method outperforms the previous approaches significantly.}, organization = {Andrés Iglesias and Akemi Gálvez have received funding from the project PDE-GIR of the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 778035, the Spanish Ministry of Science, Innovation and Universities (Computer Science National Program) under grant TIN2017–89275-R of the Agencia Estatal de Investigación and European Funds EFRD (AEI/FEDER, UE). Iztok Fister acknowledges financial support from the Slovenian Research Agency (Grant No. P2-0041). Iztok Fister Jr. acknowledges financial support from the Slovenian Research Agency (Grant No. P2-0057).}, publisher = {Elsevier Limited}, publisher = {Advanced Engineering Informatics, 2021, 47, 101222}, title = {Modified OFS-RDS bat algorithm for IFS encoding of bitmap fractal binary images}, author = {Gálvez Tomida, Akemi and Iglesias Prieto, Andrés and Díaz Severiano, José Andrés and Fister, Iztok and López Uriarte, Joaquin and Fister, Iztok Jr.}, }