Enhanced image processing methods for GMR array inspections of multilayer metallic structures.

The objective of this paper is to present a comprehensive approach to image processing for Giant Magnetoresistive (GMR) array sensors with sheet current sources for the inspection of fatigue cracks in complex metallic structures. The approach incorporates optimal phase angle adjustment, array sensitivity compensation, fastener site identification, an adaptive edge evaluation and removal algorithm and a classification metric. Processing examples are presented that highlight the benefits of these algorithms for improving crack detection for challenging edge and fastener spacing conditions. [ABSTRACT FROM AUTHOR]