Image Processing Reference
In-Depth Information
6. Conclusion
Three variants of a recent digital signal processing procedure for ultrasonic NDE, based on
the scanning with a small number of transducers sized to work in near field conditions
(located at two perpendicular planes to obtain different ultrasonic perspectives), are
evaluated. They originate distinct techniques to fuse echo information coming from two
planes: time-domain, linear time-frequency, and WVT based, 2D combination methods.
dB
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a) time domain, linear scale b) time domain, scale in dB
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c) wavelet, L =2, linear scale d) wavelet, L =2, scale in dB
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e) WVT, L =2, linear scale f) WVT, L =2, scale in dB
Fig. 9. Different 2D representations after combination of real traces in experiments type-II,
with linear scale (a, c, e) and logarithmic scale (b, d, f).
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