Detection of cartographic projection based on set of points with known coordinates in the map. Repeated comparison of pairs of identical points (both in the analyzed and the reference maps) with the aim of finding two „most similar“ sets of identical points.
Four proposed algorithms have an ability to detect some cartographic projection in normal position. Detection for first two criteria is based on the similarity transformation using the local and global transformation key to testing of the parameters.
Further two criteria are based on the auxiliary geometric structures (Voronoi diagrams) constructed over both tested datasets to assess the similarity of two Voronoi diagrams. Mentioned detection methods were subject of four comparative tests.