Spatial-temporal signal processing for subsurface thermographic imaging

Steven M. Shepard; James R. Lhota

doi:10.1117/12.497523

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1 April 2003 Spatial-temporal signal processing for subsurface thermographic imaging

Steven M. Shepard; James R. Lhota

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Proceedings Volume 5073, Thermosense XXV; (2003) https://doi.org/10.1117/12.497523
Event: AeroSense 2003, 2003, Orlando, Florida, United States

Abstract

Analysis and processing of thermographic NDT data has been primarily based on either visual analysis of single images acquired during the cooling sequence, or examination of a contrast curve based on comparison to a defect free reference region. Analysis of the sequence is complicated by the fact that the surface temperature of the sample decreases monotonically over a large dynamic range, yet the temperature differences generated by subsurface features may be small by comparison. A simple linearization operation can be performed on the entire sequence so that the time history of each pixel behaves in a manner similar to that of the contrast curve. The linearized data allows visualization of the entire sequence in a fixed dynamic range that is small enough to allow visualization of weak features, as well as presentation of the data in a line slice manner similar to an ultrasonic b-scan.

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Steven M. Shepard and James R. Lhota "Spatial-temporal signal processing for subsurface thermographic imaging", Proc. SPIE 5073, Thermosense XXV, (1 April 2003); https://doi.org/10.1117/12.497523

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