Subject of this paper is triangulation of given domain also called as mesh generation. Overview of main mesh types (structured, unstructured and hybrid) is given. Groups of triangulation methods are defined and include collective triangulation, incremental triangulation, pliant mesh generation with post-triangulation and plaint mesh generation with retriangulation. Delaunay triangulation is described in greater detail and variuos Delaunay triangulation algorithms are presented including use of Delaunay triangulation for anisotropic mesh generation and method to generate Constrained Delaunay triangulation. Greedy insertion Delaunay and data dependent allgorithms are developed for hight fields surface aproximation. Significant improvements are made to these algorithms including faster recalculation, node selection and use of supplementary data sets in order to maximise efficiency of calculations. Main criteria to evaluate developed algorithms is overall error of approximation and speed of calculation. Data dependent algorithm generates better quality mesh (less approximation error), however Delaunay triangulation algorithm is significantly faster. Results and conclusions are presented at the end of paper.

Šiame darbe yra nagrinėjamas piršto antspaudo atpažinimo uždavinio viena iš sudedamųjų dalių: skaitmeninės informacijos apie piršto antspaudą gavimas. Aprašomas metodas, paremtas kreivių kreivumų įvertinimu bei minimalaus žiedo sąvoka. Taip pat, aprašytas naujas Delaunė trianguliacijos radimo, minimalaus žiedo skaičiavimo bei kreivių kreivumų įvertinimo algoritmai. Darbo tikslas - pagerinti piršto antspaudo atpažinimo algoritmo kokybę, bei greitį. / The recognition of fingerprint is discussed in this article. The goal of this work is to increase the quality of fingerprint recognition method, and to improve algorithm speed. The new method of fingerprint data for fingerprint matching is analyzed. It concentrates on calculating values of curve curvatures, and minimum-width annuli. Some new methods of evaluation of this properties are described step by step.