Proceedings of the 18th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications Volume 1: GRAPP Acronym: GRAPP 2023/VISIGRAPP Event held on: February 19-21, 2023, in Lisbon, Portugal Editors: A. Augusto Sousa 1 , Thomas Bashford-Rogers 2 and Kadi Bouatouch 3 Affiliations: 1 FEUP/INESC TEC, Portugal , 2 University of Warwick, United Kingdom , 3 IRISA, University of Rennes 1, France Vol. 1 - 978-989-758-634-7 Vol. 2 - 978-989-758-634-7 Vol. 3 - 978-989-758-634-7 Vol. 4 - 978-989-758-634-7 Vol. 5 - 978-989-758-634-7