A fast and practical grid based algorithm for point-feature label placement problem

Point-feature label placement (PFLP) is a major area of interest within the filed of automated cartography, geographic information systems (GIS), and computer graphics. The objective of a label placement problem is to assign a label to each point feature so as to avoid conflicts, considering the cartographic conventions. According to computational complexity analysis, the labeling problem has been shown to be NP-Hard. It is also very challenging to find a computationally efficient algorithm that is intended to be used for both static and dynamic map labeling. In this paper, we propose a heuristic method that first fills the free space of the map with rectangular shape labels like a grid and then matches the corresponding point feature with the nearest label. The performance of the proposed algorithm was evaluated through empirical tests with different data set sizes. The results show that our algorithm based on grid placement of labels is a useful, fast and practical solution for automated map labeling.