Using data mining methods for improvement of product and process quality. - Manfred Estler; Ralf Hilpert; Niels Kiupel; Sergio Soravia (ECC, 1999)

Automatic Analysis of Sewer Pipes Based on Unrolled Monocular Fisheye Images. - Johannes Künzel; Thomas Werner; Ronja Möller; Peter Eisert; Jan Waschnewski; Ralf Hilpert (CoRR, 2019)