Advanced Art Authentication in Oil Paintings Using Precise 3D Morphological Analysis of Craquelure Patterns

The development of scientific technology for art authentication have elicited multidimensional evidence to distinguish forgeries from original artworks. Here, we analyzed three-dimensional morphology of cracks that contain information such as painting features of artworks using an optical coherence tomography (OCT). The forgeries were produced by an expert from the original oil paintings with cracks that occur as paint drying, canvas aging, and physical damage. The parameters such as shape, width, and depth were compared based on cross-sectional images of original and fake cracks. The shapes of original cracks were a rectangular and an inverted triangle, but fake cracks were a relatively simple inverted triangle. The original cracks were as deep as the thickness of the upper layer and mostly have ‘thin/deep' or 'wide/shallow'. The fake cracks were observed as 'thin/shallow' or 'wide/deep'. This study will improve the understanding of the crack characteristics and promote development of techniques for art authenticity.

Multiple Authority Delegation in Art Authentication

In this paper, I expand upon the research on authority delegation begun by Overgaard and myself in our 2016 paper Authority Delegation. I argue that singular authority delegation – in which a community delegates authority over a given topic to a single expert community – should be distinguished from cases of multiple authority delegation. A community engages in multiple authority delegation iff that community delegates authority over a given topic to more than one expert community. Furthermore, multiple authority delegation can be further divided into two types: hierarchical and non-hierarchical. I examine two cases of authority delegation in the art market and argue that these cases model instances of hierarchical authority delegation.Suggested Modifications[Sciento-2017-0007]: Accept the following definitions of subtypes of authority delegation: Singular authority delegation ≡ community A is said to engage in a relationship of singular authority delegation over topic x iff community A delegates authority over topic x to exactly one community.Multiple authority delegation ≡ community A is said to engage in a relationship of multiple authority delegation over topic x iff community A delegates authority over topic x to more than one community. Hierarchical authority delegation ≡ a sub-type of multiple authority delegation where different communities are delegated different degrees of authority over topic x.Non-hierarchical authority delegation ≡ a sub-type of multiple authority delegation where different communities are delegated the same degree of authority over topic x. [Sciento-2017-0008]: Accept the following reconstruction of the contemporary authority delegation structure in the art market regarding the works of Monet: A work claimed to be by Monet is authentic if it is considered authentic by the Wildenstein Institute.[Sciento-2017-0009]: Accept the following reconstruction of the contemporary authority delegation structure in the art market regarding the works of Picasso: A work claimed to be by Picasso is authentic if it is has been certified as authentic by both Maya Widmaier-Picasso and Claude Ruiz-Picasso.[Sciento-2017-0010]: Accept the following reconstruction of the authority delegation structure in the art market regarding the works of Modigliani between 1997 and 2015: A work claimed to be by Modigliani is authentic iff (1) it is in the Ceroni catalogue raisonné or (2) if it is not in catalogue and has been certified as authentic by Marc Restellini.[Sciento-2017-0011]: Accept the following reconstruction of the contemporary authority delegation structure in the art market regarding the works of Renoir: A work claimed to be by Renoir is authentic iff (1) it has been certified as authentic by the Wildenstein institute or (2) it has not been dismissed by the Wildenstein institute and it is included in the Bernheim-Jeune catalogue.

Use of infrared hyperspectral imaging as an aid for paint identification

Art authentication is a complicated process that often requires the extensive study of high value objects. Although a series of non-destructive techniques is already available for art scientists, new techniques, extending current possibilities, are still required. In this paper, the use of a novel mid-infrared tunable imager is proposed as an active hyperspectral imaging system for art work analysis. The system provides access to a range of wavelengths in the electromagnetic spectrum (2500–3750 nm) which are otherwise difficult to access using conventional hyperspectral imaging (HSI) equipment. The use of such a tool could be beneficial if applied to the paint classification problem and could help analysts map the diversity of pigments within a given painting. The performance of this tool is demonstrated and compared with a conventional, off-the-shelf HSI system operating in the near infrared spectral region (900–1700 nm). Various challenges associated with laser-based imaging are demonstrated and solutions to these challenges as well as the results of applying classification algorithms to datasets captured using both HSI systems are presented. While the conventional HSI system provides data in which more pigments can be accurately classified, the result of applying the proposed laser-based imaging system demonstrates the validity of this technique for application in art authentication tasks.