Recognition of Cuneiform Inscription Signs by use of a Hybrid-Optoelectronic Correlator Device

Author(s): Nazif Demoli, Jörn Kamps, Sven Krüger, Hartmut Gruber, and Günther Wernicke

Abstract:

“A hybrid-optoelectronic correlator device and an algorithm are proposed for recognizing cuneiform inscription signs. The device is based on the extended correlator architecture with three liquid-crystal display(s) (LCD)s and three light detectors: one CCD camera for capturing the input image, one LCD for displaying the input image, two LCDs for the complex correlation filter (amplitude and phase parts), and two detectors for measuring the total and peak intensities of the output correlation information. The recognition algorithm is designed to allow automatic as well as real-time processing. The recognition results are given for the cuneiform signs impressed on an original clay tablet. The investigated tablet (VAT 12890 of the Pergamon Museum, Berlin, Germany) was found in Bogazköy (Hattusha) and dates from the 14th century B.C. It is a fragment of the Epic of Gilgamesh in the Akkadian language with a large number of the sign samples.”

Link to Publications Page

Publication: Applied Optics
Issue/Year: Applied Optics, Vol. 41, Issue 23, pp. 4762-4774, 2002
DOI: 10.1364/AO.41.004762

Anwendung von Wavelet-Filtern in einem optischen Prozessor zur automatischen Fehlererkennung in Interferogrammen

Author(s): G. Wernicke, S. Krüger, F. Kallmeyer, H. Gruber, Wolfgang Osten, D. Kayser, N. Demoli

Abstract:

“Die Wavelet-Transformation hat sich als leistungsfähiges Werkzeug bei der Erkennung von Strukturen mit definierter räumlicher Auflösung erwiesen. Im vorliegenden Aufsatz wird die Filter-Prozedur in der komplexen Ebene nicht nur auf numerische Simulationen erweitert, sondern auch in optischen Experimenten durch einen zweifachen Frequenzebenen-Korrelator angewandt. Hierzu wurden drei räumliche Lichtmodulatoren (SLM) auf der Basis von Twisted-Nematic-Flüssigkristallen verwendet.”

Link to Publications Page

Publication: tm – Technisches Messen
Issue/Year: tm – Technisches Messen, Volume: 69, Issue: 5, Page 236
DOI: 10.1524/teme.2002.69.5.236

Optical processing for the detection of faults in interferometric patterns

Author(s): Frank Kallmeyer, Sven Krueger, Guenther Wernicke, Hartmut Gruber, Nazif Demoli, Wolfgang Osten, Daniel Kayser

Abstract:

“The detection and classification of faults is a major task for optical nondestructive testing in industrial quality control. Interferometric fringes, obtained by real-time optical measurement methods, contain a large amount of image data with information about possible defect features. This mass of data must be reduced for further evaluation. One possible way is the filtering of these images applying the adaptive wavelet transform. The wavelet transform has been proved to be a capable tool in the detection of structures with definite spatial resolution. In this paper it is shown the extraction and classification of disturbances in interferometric fringe patterns, the application of several wavelet functions with different parameters for the detection of faults, and the combination of wavelet filters for fault classification. Furthermore the implementation of complex valued wavelet filters and correlation filters is shown. We will present an algorithm to classify interferometric fringe patterns. In order to achieve real-time processing a hybrid opto-electronic system with a digital image processing and an optical correlation module is favored. The calculated wavelet filters are implemented into the optical correlator system that is based on liquid-crystal spatial light modulators. So, all discussed items were verified experimentally in the optical setup. ”

Link to Publications Page

Publication: SPIE Proceedings
Issue/Year: Proc. SPIE, Vol. 4777, 371 (2002)
DOI: 10.1117/12.472237