Combination of topology and structural information for damages and deterioration analysis of artworks

Abstract

Because artworks are a major part of our culture their preservation is of great importance and therefore they need to be protected from any damage. But the change of environmental conditions like temperature or humidity leads to internal stress, which can result in different defects like delaminations or cracks. The deteriorations occurring due to ageing or transport are often small and invisible, but they can enlarge and produce new irreversible damages. Therefore it is important to detect small changes in the surface as well as deteriorations under the surface. A combination of fringe projection and shearography data is a very suitable method to fulfill this task. While fringe projection is used to determine the surface structure, the shearography gives information about the strain occurring due to loading, which allows conclusions about weaknesses in the internal structure. We optimized both techniques for the use in the preservation of artwork and combined the resulting data by a mapping process. In this paper we present the advantages and also the limits, which need to overcome.

3D shape shearography technique for surface strain measurement of free-form objects

“…Another approach uses virtual reality techniques and strain data mapping onto 2D or 3D surfaces (e.g., a canvas painting) [13][14][15][16], CAD models, or real surface profiles measured with various topography or shape measuring techniques [12,17,18]. In some cases, UV-mapping [15,19] is used for fusion of the topography and shearography data.…”

“…Another approach uses virtual reality techniques and strain data mapping onto 2D or 3D surfaces (e.g., a canvas painting) [13][14][15][16], CAD models, or real surface profiles measured with various topography or shape measuring techniques [12,17,18]. In some cases, UV-mapping [15,19] is used for fusion of the topography and shearography data. Several developments used structured light projectors to measure the shape [14][15][16] or to project the shearography phase maps on the object for interactive visualization [20,21].…”

“…In some cases, UV-mapping [15,19] is used for fusion of the topography and shearography data. Several developments used structured light projectors to measure the shape [14][15][16] or to project the shearography phase maps on the object for interactive visualization [20,21]. Although the 3D shape measurement approach was mentioned in a short report [22], the authors did not report on the use of the surface data for correction of the shear distances or the sensitivity vectors.…”