Enhanced image processing for infrared non-destructive testing

2014 ◽  
Vol 22 (4) ◽  
Author(s):  
F. Lopez ◽  
X. Maldague ◽  
C. Ibarra-Castanedo
Keyword(s):  
Signal To Noise Ratio ◽  
Signal Reconstruction ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Multivariate Statistical ◽  
Depth Analysis ◽  
Thermal Data ◽  
Signal Contrast ◽  
Pulsed Phase Thermography ◽  
Non Destructive

AbstractThis paper presents a review and in-depth analysis of three of the most popular techniques for processing PT images: differential absolute contrast, thermographic signal reconstruction and pulsed phase thermography. The fundamental concepts of the three techniques are reviewed and their application on thermal data obtained from the PT inspection on a carbon fibre reinforced specimen is analysed. Furthermore, a new promissory technique based on multivariate statistical analysis is also introduced and evaluated. The performance of the techniques is evaluated in terms of the signal-to-noise ratio at maximum signal contrast.

Review on Non-Destructive Testing Technique of Eddy Current Pulsed Thermography

2015 ◽  
Vol 742 ◽  
pp. 128-131 ◽  
Author(s):  
Jian Min Zhou ◽  
Jun Yang ◽  
Qi Wan
Keyword(s):  
Eddy Current ◽  
Signal Reconstruction ◽  
Infrared Image ◽  
Principal Component ◽  
Research Progress ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Pulsed Thermography ◽  
Pulsed Phase Thermography ◽  
Non Destructive

This paper introduces the theory of eddy current pulsed thermography and expounds the research status of eddy current pulsed thermography in application and information extraction. Thermographic signal reconstruction, pulsed phase thermography, principal component analysis were introuduced in this paper and listed some fusion multiple methods to acquire information from infrared image. At last, it summarizes research progress, existing problem and deelopment of eddy current pulsed thermography.

Ultrasound Imaging Using Multilayer Synthetic Aperture Focusing

2010 ◽  
Author(s):  
Martin H. Skjelvareid ◽  
Yngve Birkelund
Keyword(s):  
Signal To Noise Ratio ◽  
Synthetic Aperture ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Wave Velocities ◽  
Homogenous Medium ◽  
Synthetic Aperture Focusing ◽  
Original Time ◽  
Non Destructive ◽  
Test Objects

Synthetic aperture focusing techniques (SAFT) have already been studied within several fields of non-destructive testing, but so far only with a single, relatively homogenous medium. In this article, we modify the original time-domain SAFT in order to image the interior of a multilayer structure. Standard focusing techniques assume that the wave velocity is constant within the volume to be imaged. The concept of the root-mean-square (RMS) velocity is used here to modify the classical delay-and-sum algorithm to handle layers with differing wave velocities. A scheme for iteratively using this to estimate the interfaces between the layers is also presented. The proposed method is demonstrated on ultrasonic B-scans of two test objects immersed in water, and it is shown that the increased lateral resolution and signal-to-noise ratio of standard SAFT is extended to the multilayer case. The increased resolution also makes it possible to accurately estimate the interfaces between consecutive layers, as long as the preceding interfaces are relatively smooth.

scholarly journals A Versatile Illumination System for Real-Time Terahertz Imaging

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3993
Author(s):  
Jean-Baptiste Perraud ◽  
Adrien Chopard ◽  
Jean-Paul Guillet ◽  
Pierre Gellie ◽  
Antoine Vuillot ◽  
...  
Keyword(s):  
Real Time ◽  
Signal To Noise Ratio ◽  
Beam Steering ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Full Field ◽  
Illumination System ◽  
Optimized Distribution ◽  
Non Destructive ◽  
Field Imaging

Terahertz technologies are attracting strong interest from high-end industrial fields, and particularly for non-destructive-testing purposes. Currently lacking compactness, integrability as well as adaptability for those implementations, the development and commercialisation of more efficient sources and detectors progressively ensure the transition toward applicative implementations, especially for real-time full-field imaging. In this work, a flexible illumination system, based on fast beam steering has been developed and characterized. Its primary goal is to suppress interferences induced by the coherence length of certain terahertz sources, spoiling terahertz images. The second goal is to ensure an enhanced signal-to-noise ratio on the detector side by the full use and optimized distribution of the available power. This system provides a homogeneous and adjustable illumination through a simplified setup to guarantee optimum real-time imaging capabilities, tailored to the sample under inspection. Working toward industrial implementations, different illumination process are conveniently assessed as a result of the versatility of this method.

scholarly journals Comparison of Cooled and Uncooled IR Sensors by Means of Signal-to-Noise Ratio for NDT Diagnostics of Aerospace Grade Composites

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3381 ◽  
Author(s):  
Shakeb Deane ◽  
Nicolas P. Avdelidis ◽  
Clemente Ibarra-Castanedo ◽  
Hai Zhang ◽  
Hamed Yazdani Nezhad ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Non Destructive Testing ◽  
Signal To Noise ◽  
Destructive Testing ◽  
Ir Camera ◽  
Thermal Cameras ◽  
Aerial Vehicle ◽  
Noise Ratio ◽  
Processing Techniques ◽  
Non Destructive

This work aims to address the effectiveness and challenges of non-destructive testing (NDT) by active infrared thermography (IRT) for the inspection of aerospace-grade composite samples and seeks to compare uncooled and cooled thermal cameras using the signal-to-noise ratio (SNR) as a performance parameter. It focuses on locating impact damages and optimising the results using several signal processing techniques. The work successfully compares both types of cameras using seven different SNR definitions, to understand if a lower-resolution uncooled IR camera can achieve an acceptable NDT standard. Due to most uncooled cameras being small, lightweight, and cheap, they are more accessible to use on an unmanned aerial vehicle (UAV). The concept of using a UAV for NDT on a composite wing is explored, and the UAV is also tracked using a localisation system to observe the exact movement in millimetres and how it affects the thermal data. It was observed that an NDT UAV can access difficult areas and, therefore, can be suggested for significant reduction of time and cost.

Effects of Magnetic Concentrator on MFL Signals Using FEA

2011 ◽  
Vol 204-210 ◽  
pp. 1956-1959
Author(s):  
Qiang Song
Keyword(s):  
Signal To Noise Ratio ◽  
Axial Component ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Element Analysis ◽  
Leakage Flux ◽  
Testing Method ◽  
Detection Schemes ◽  
Non Destructive ◽  
Flux Leakage

Magnetic flux leakage (MFL) is a non-destructive testing method used to inspect ferrous materials. However, there are a variety of factors that can affect the MFL inspection tool’s ability to detect and characterize anomalies. MFL signals obtained during the inspection of pipes have been simulated using 3D finite element analysis (FEA) and the effects of magnetic concentrator on MFL signals are investigated. Measurements of the leakage flux with various defect depths or widths indicate that the axial component of MFL are improved by magnetic concentrator with the result that significant advantages could be obtained in defect detection schemes, in that the signal to noise ratio (SNR) of MFL signals can be improved by magnetic concentrator.

Denoising Method of Wood Defect Images Based on Wavelet Packet Combined with Gray-Scale Morphological Filtering

2011 ◽  
Vol 480-481 ◽  
pp. 153-158
Author(s):  
Da Wei Qi ◽  
Xi Yang ◽  
Yuan Yuan Zhou
Keyword(s):  
Signal To Noise Ratio ◽  
Wavelet Packet ◽  
Low Frequency ◽  
Non Destructive Testing ◽  
Gray Scale ◽  
Destructive Testing ◽  
Denoising Method ◽  
Morphological Filtering ◽  
Non Destructive ◽  
Excessive Noise

Excessive noise was joined with the acquiring wood defect images process in wood non-destructive testing. The image quality was affected. Wavelet packet transform could decompose high frequency and low frequency of signal at the same time. There were characteristics of open and closed in Gray-scale Morphology. Denoising method of wood defect images based on wavelet packet combined with gray-scale morphological filtering was proposed. Compared with the traditional denoising method, the method received better Peak Signal to Noise Ratio (PSNR) and visual effect. Experimental results verified the feasibility and effectiveness of this method.

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