Surface Displacement Measurements of Artworks: New Data Processing for Speckle Pattern Interferometry
Curators have developed preventive conservation strategies and usually try to control the temperature (T) and relative humidity (RH) variations in the museum rooms to stabilise the artworks. The control systems chosen by museums depend on the size and age of the building, the financial means and the...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-11-01
|
| Series: | Applied Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3417/12/23/11969 |
| _version_ | 1797463684704894976 |
|---|---|
| author | Jessica Auber--Le Saux Vincent Detalle Xueshi Bai Michalis Andrianakis Nicolas Wilkie-Chancellier Vivi Tornari |
| author_facet | Jessica Auber--Le Saux Vincent Detalle Xueshi Bai Michalis Andrianakis Nicolas Wilkie-Chancellier Vivi Tornari |
| author_sort | Jessica Auber--Le Saux |
| collection | DOAJ |
| description | Curators have developed preventive conservation strategies and usually try to control the temperature (T) and relative humidity (RH) variations in the museum rooms to stabilise the artworks. The control systems chosen by museums depend on the size and age of the building, the financial means and the strategies that can be adapted. However, there is a lack of methods that can monitor mechanical changes or chemical reactions of objects in real-time or regularly. It would therefore ideally be preferable to monitor each of them to alert them to preserve them. For this purpose, a non-destructive, non-contact, full-field technique, Digital Holographic Speckle Pattern Interferometry (DHSPI), has already been developed and allows direct tracking of changes on the surface of artworks. This technique is based on phase-shifting speckle interferometry and gives the deformation of the surface below the level of the micro-meter of the analysed object. In order to monitor the deformation continuously, a large number of images are acquired by DHSPI and have to be processed. The existing process consists of removing noise from the interferogram, unwrapping this image, and deriving and displaying a 2D or 3D deformation map. In order to improve the time and accuracy of processing the imaging data, a simpler and faster processing method is developed. Using Matlab<sup>®</sup>, a denoising methodology for the interference pattern generated during data acquisition is created, based on a stationary wavelet transform. The unwrapped image is calculated using the CPULSI (Calibrated Phase Unwrapping based on Least-Squares and Iterations) algorithm as it gives the fastest results among the tested methods. The unwrapped phase is then transformed into surface displacement. This process performs these steps for each interferogram automatically. It allows access to 2D or 3D deformation maps. |
| first_indexed | 2024-03-09T17:54:14Z |
| format | Article |
| id | doaj.art-6c681db2dc27401aa6baf630b84d5b2f |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-09T17:54:14Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-6c681db2dc27401aa6baf630b84d5b2f2023-11-24T10:28:47ZengMDPI AGApplied Sciences2076-34172022-11-0112231196910.3390/app122311969Surface Displacement Measurements of Artworks: New Data Processing for Speckle Pattern InterferometryJessica Auber--Le Saux0Vincent Detalle1Xueshi Bai2Michalis Andrianakis3Nicolas Wilkie-Chancellier4Vivi Tornari5C2RMF, Centre de Recherche et de Restauration des Musées de France, 14 Quai François Mitterrand, 75001 Paris, FranceC2RMF, Centre de Recherche et de Restauration des Musées de France, 14 Quai François Mitterrand, 75001 Paris, FranceC2RMF, Centre de Recherche et de Restauration des Musées de France, 14 Quai François Mitterrand, 75001 Paris, FranceFORTH, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas (IESL-FORTH), N. Plastira 100, 71110 Heraklion, GreeceSATIE, Systèmes et Applications des Technologies de l’Information et de l’Energie, CY Cergy-Paris Université, ENS Paris-Saclay, CNRS UMR 8029, 5 Mail Gay Lussac, 95031 Neuville sur Oise, FranceFORTH, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas (IESL-FORTH), N. Plastira 100, 71110 Heraklion, GreeceCurators have developed preventive conservation strategies and usually try to control the temperature (T) and relative humidity (RH) variations in the museum rooms to stabilise the artworks. The control systems chosen by museums depend on the size and age of the building, the financial means and the strategies that can be adapted. However, there is a lack of methods that can monitor mechanical changes or chemical reactions of objects in real-time or regularly. It would therefore ideally be preferable to monitor each of them to alert them to preserve them. For this purpose, a non-destructive, non-contact, full-field technique, Digital Holographic Speckle Pattern Interferometry (DHSPI), has already been developed and allows direct tracking of changes on the surface of artworks. This technique is based on phase-shifting speckle interferometry and gives the deformation of the surface below the level of the micro-meter of the analysed object. In order to monitor the deformation continuously, a large number of images are acquired by DHSPI and have to be processed. The existing process consists of removing noise from the interferogram, unwrapping this image, and deriving and displaying a 2D or 3D deformation map. In order to improve the time and accuracy of processing the imaging data, a simpler and faster processing method is developed. Using Matlab<sup>®</sup>, a denoising methodology for the interference pattern generated during data acquisition is created, based on a stationary wavelet transform. The unwrapped image is calculated using the CPULSI (Calibrated Phase Unwrapping based on Least-Squares and Iterations) algorithm as it gives the fastest results among the tested methods. The unwrapped phase is then transformed into surface displacement. This process performs these steps for each interferogram automatically. It allows access to 2D or 3D deformation maps.https://www.mdpi.com/2076-3417/12/23/11969digital speckle pattern interferometrydenoisingunwrappingcultural heritagepreventive conservationdeformation maps |
| spellingShingle | Jessica Auber--Le Saux Vincent Detalle Xueshi Bai Michalis Andrianakis Nicolas Wilkie-Chancellier Vivi Tornari Surface Displacement Measurements of Artworks: New Data Processing for Speckle Pattern Interferometry Applied Sciences digital speckle pattern interferometry denoising unwrapping cultural heritage preventive conservation deformation maps |
| title | Surface Displacement Measurements of Artworks: New Data Processing for Speckle Pattern Interferometry |
| title_full | Surface Displacement Measurements of Artworks: New Data Processing for Speckle Pattern Interferometry |
| title_fullStr | Surface Displacement Measurements of Artworks: New Data Processing for Speckle Pattern Interferometry |
| title_full_unstemmed | Surface Displacement Measurements of Artworks: New Data Processing for Speckle Pattern Interferometry |
| title_short | Surface Displacement Measurements of Artworks: New Data Processing for Speckle Pattern Interferometry |
| title_sort | surface displacement measurements of artworks new data processing for speckle pattern interferometry |
| topic | digital speckle pattern interferometry denoising unwrapping cultural heritage preventive conservation deformation maps |
| url | https://www.mdpi.com/2076-3417/12/23/11969 |
| work_keys_str_mv | AT jessicaauberlesaux surfacedisplacementmeasurementsofartworksnewdataprocessingforspecklepatterninterferometry AT vincentdetalle surfacedisplacementmeasurementsofartworksnewdataprocessingforspecklepatterninterferometry AT xueshibai surfacedisplacementmeasurementsofartworksnewdataprocessingforspecklepatterninterferometry AT michalisandrianakis surfacedisplacementmeasurementsofartworksnewdataprocessingforspecklepatterninterferometry AT nicolaswilkiechancellier surfacedisplacementmeasurementsofartworksnewdataprocessingforspecklepatterninterferometry AT vivitornari surfacedisplacementmeasurementsofartworksnewdataprocessingforspecklepatterninterferometry |