Osten, W.W.OstenElandaloussi, F.F.ElandaloussiMieth, U.U.Mieth2022-03-092022-03-092002https://publica.fraunhofer.de/handle/publica/34178510.1117/12.484525In this contribution we give a description of two modern approaches for the solution of identification problems in HNDT. One approach uses an active strategy for the classification of fault-indicating fringe patterns that can be described by the term "Recognition by Synthesis". The other approach is more passive but uses a high amount of a-priori knowledge about the appearance of material faults in fringe patterns. The derivation of this a-priori knowledge is supported by the mathematical modeling of the connection between the visible fault indicating pattern and its cause, the hidden material fault under the surface.en620conference paper