Citation: Blana, N.; Kavadas, I.; Tsoulos, L. A Constraint-Based Generalization Model Incorporating a Quality Control Mechanism. Geographies 2023, 3, 321–343. https://doi.org/10.3390/ geographies3020017 Academic Editors: Vassilios Krassanakis, Andriani Skopeliti, Merve Keskin, Pawel Cybulski and Charalampos Kontoes Received: 31 January 2023 Revised: 2 April 2023 Accepted: 24 April 2023 Published: 8 May 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Article A Constraint-Based Generalization Model Incorporating a Quality Control Mechanism Natalia Blana 1 , Ioannis Kavadas 2 and Lysandros Tsoulos 1, * 1 Cartography Laboratory, School of Rural, Surveying and Geoinformatics Engineering, National Technical University of Athens, 15780 Zografou, Greece 2 Internal Quality Unit, Hellenic Cadastre, 15562 Holargos, Greece * Correspondence: lysandro@central.ntua.gr Abstract: Automation in map production has created the need for modeling the map composition process. Generalization is the most critical process in map composition, with considerable impact on the quality of features portrayed on the maps. Modeling of the generalization process has been an area of research for several years in the international cartographic community. Constraint-based generalization modeling prevailed, and it is evolving to an agent model or to other optimization models. The generalization model presented in this paper is based on constraint-based modeling. It introduces the standardization of the semantic and cartographic generalization process together with an evaluation mechanism for the assessment of the quality of the resulting cartographic data considering simultaneously the preservation of the shape of the portrayed linear and area features. For cartographers, quality management is a key factor in creating an evidence-based, reliable product. To achieve this objective, cartographers, drawing on international experience, should implement a quality policy and adopt a quality management system (QMS) as an integral part of the map production process, starting with the quality assessment of the input data and finishing with the evaluation of the final product. Keywords: map quality; data quality model; semantic and cartographic generalization; generalization modeling; shape evaluation 1. Introduction As a means of depicting the geography of an area, maps aim to store and display the geographic information of the area, considering the geographic features and their relationships. When considering the purpose of the map, scale restricts the display of geospatial entities (features’ arrangement and their relationships), which is implemented through generalization (semantic and cartographic). The selection of the features to be depicted, along with their accuracy and clarity in portrayal together with the integrity of their relationships, are the goal of generalization. Generalization is the most critical transformation in cartography, causing modification of features’ shape and—occasionally—a partial to complete elimination of spatial informa- tion. Generalization modeling aims to control the process of generalization and has been a field of extensive research since the 1990s. A turning point in generalization modeling was the development of the constraint-based generalization model, which approaches general- ization holistically through the integration of an evaluation mechanism for assessing the state of the data before, during and after generalization. This article elaborates on the development of a constraint-based generalization model integrating a quality model with a shape evaluation mechanism, which was introduced par- tially in the previous work of the authors [1,2]. Considering generalization as the transition from a geospatial database (digital landscape model—DLM) to a cartographic one (digital cartographic model—DCM) as proposed by [3] and adopted by several European national Geographies 2023, 3, 321–343. https://doi.org/10.3390/geographies3020017 https://www.mdpi.com/journal/geographies