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Effects of the Ground Resolution and Thresholding on Crack Width Measurements

When diagnosing the condition of a structure, it is necessary to measure the widths of any existing cracks in the structure. To ensure safety when relying on images of cracks, the selected imaging parameters and processing technology must be well understood. In this study, the effects of the ground...

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Detalles Bibliográficos
Autores principales: Cho, Hyunwoo, Yoon, Hyuk-Jin, Jung, Ju-Yeong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6111740/
https://www.ncbi.nlm.nih.gov/pubmed/30103551
http://dx.doi.org/10.3390/s18082644
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author Cho, Hyunwoo
Yoon, Hyuk-Jin
Jung, Ju-Yeong
author_facet Cho, Hyunwoo
Yoon, Hyuk-Jin
Jung, Ju-Yeong
author_sort Cho, Hyunwoo
collection PubMed
description When diagnosing the condition of a structure, it is necessary to measure the widths of any existing cracks in the structure. To ensure safety when relying on images of cracks, the selected imaging parameters and processing technology must be well understood. In this study, the effects of the ground sample distance and threshold values on the crack width measurement error are analyzed from a theoretical perspective. Here, the main source of such errors is assumed to be due to the mixed pixel phenomena in the left and right boundary pixels. Thus, a mathematical model is proposed in which the intensity changes in these pixels are computed via an equation. In addition, the relationship between the error and error probability distribution is represented with an equation based on the threshold values and mean error. Upon analysis, it was found that the threshold value that minimizes the error is at the mid-point between the background and foreground, and the probabilistic nature of the error indicates that it is theoretically possible to predict both the error and its probability distribution. The proposed model was validated using artificial images.
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spelling pubmed-61117402018-08-30 Effects of the Ground Resolution and Thresholding on Crack Width Measurements Cho, Hyunwoo Yoon, Hyuk-Jin Jung, Ju-Yeong Sensors (Basel) Article When diagnosing the condition of a structure, it is necessary to measure the widths of any existing cracks in the structure. To ensure safety when relying on images of cracks, the selected imaging parameters and processing technology must be well understood. In this study, the effects of the ground sample distance and threshold values on the crack width measurement error are analyzed from a theoretical perspective. Here, the main source of such errors is assumed to be due to the mixed pixel phenomena in the left and right boundary pixels. Thus, a mathematical model is proposed in which the intensity changes in these pixels are computed via an equation. In addition, the relationship between the error and error probability distribution is represented with an equation based on the threshold values and mean error. Upon analysis, it was found that the threshold value that minimizes the error is at the mid-point between the background and foreground, and the probabilistic nature of the error indicates that it is theoretically possible to predict both the error and its probability distribution. The proposed model was validated using artificial images. MDPI 2018-08-12 /pmc/articles/PMC6111740/ /pubmed/30103551 http://dx.doi.org/10.3390/s18082644 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Cho, Hyunwoo
Yoon, Hyuk-Jin
Jung, Ju-Yeong
Effects of the Ground Resolution and Thresholding on Crack Width Measurements
title Effects of the Ground Resolution and Thresholding on Crack Width Measurements
title_full Effects of the Ground Resolution and Thresholding on Crack Width Measurements
title_fullStr Effects of the Ground Resolution and Thresholding on Crack Width Measurements
title_full_unstemmed Effects of the Ground Resolution and Thresholding on Crack Width Measurements
title_short Effects of the Ground Resolution and Thresholding on Crack Width Measurements
title_sort effects of the ground resolution and thresholding on crack width measurements
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6111740/
https://www.ncbi.nlm.nih.gov/pubmed/30103551
http://dx.doi.org/10.3390/s18082644
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