Automatic Pigment Classification in Painted Works of Art from Diffuse Reflectance Image Data

Information about artists\u27 materials used in paintings, obtained from the analysis of limited micro-samples, has assisted conservators to better define treatment plans, and provided scholars with basic information about the working methods of the artists. Recently, macro-scale imaging systems such as visible-to-near infrared (VNIR) reflectance hyperspectral imaging (HSI) are being used to provide conservators and art historians with a more comprehensive understanding of a given work of art. However, the HSI analysis process has not been streamlined and currently requires significant manual input by experts. Additionally, HSI systems are often too expensive for small to mid-level museums. This research focused on three main objectives: 1) adapt existing algorithms developed for remote sensing applications to automatically create classification and abundance maps to significantly reduce the time to analyze a given artwork, 2) create an end-to-end pigment identification convolutional neural network to produce pigment maps that may be used directly by conservation scientists without further analysis, and 3) propose and model the expected performance of a low-cost fiber optic single point multispectral system that may be added to the scanning tables already part of many museum conservation laboratories. Algorithms developed for both classification and pigment maps were tested on HSI data collected from various illuminated manuscripts. Results demonstrate the potential of both developed processes. Band selection studies indicates that pigment identification from a small number of bands produces similar results to that of the HSI data sets on a selected number of test artifacts. A system level analysis of the proposed system was conducted with a detailed radiometric model. The system trade study confirmed the viability of using either individual spectral filters or a linear variable filter set-up to collect multispectral data for pigment identification of works of art

The public domain vs. the museum: the limits of copyright and reproductions of two-dimensional works of art

The problem of museums and public institutions handling reproductions of works in their collections is not only a legal question but also one of museum ethics. Public museums are committed to spreading knowledge and to making their collections accessible. When it comes to images of their holdings, however, they often follow a restrictive policy. Even for works in the public domain they claim copyright for their reproductive photographs. This paper offers an analysis of the different interests at stake, a short survey of important cases, and practical recommendations

Immersive Contemplation in Video Art Environments

This essay examines a form of video art -- what is called a video environment -- that calls upon as much as it departs from familiar conventions that are bound up in museum display. I argue that the way that works in this genre are housed in museums enables them to give rise to a form of contemplation, one involving immersion, that is, if not unique to this genre, then certainly demonstrated by it. My examples of video environments make a case for the coherence of this rarely experienced immersive form of contemplation, the value of which, in turn, makes a case for the genre\u27s further development

Assessment of plastics in the National Trust: a case study at Mr Straw's House

The National Trust is a charity that cares for over 300 publically accessible historic buildings and their contents across England, Wales and Northern Ireland. There have been few previous studies on preservation of plastics within National Trust collections, which form a significant part of the more modern collections of objects. This paper describes the design of an assessment system which was successfully trialled at Mr Straws House, a National Trust property in Worksop, UK. This system can now be used for future plastic surveys at other National Trust properties. In addition, the survey gave valuable information about the state of the collection, demonstrating that the plastics that are deteriorating are those that are known to be vulnerable, namely cellulose nitrate/acetate, PVC and rubber. Verifying this knowledge of the most vulnerable plastics enables us to recommend to properties across National Trust that these types should be seen as a priority for correct storage and in-depth recording

Remote and contactless infrared imaging techniques for stratigraphical investigations in paintings on canvas

AbstractIn the analysis of complex stratigraphical structures like painted artefact, infrared (IR) techniques can provide precious information about elements hidden under superficial layers of the artwork, such as pictorial features and structural defects. This paper presents a novel complementary use of reflectographic and thermographic techniques for the survey of three baroque paintings, preserved at the Chigi Palace in Ariccia (Italy). First, the IR-ITR laser scanner prototype has been used for the preliminary and remote near-IR reflectographic survey of the areas where the canvas was located. The resulting map was then used for planning the thermographic and mid-IR reflectographic studies, focusing the analyses on the most interesting areas of one of the paintings, called "La Primavera". The combination of the three imaging techniques revealed several details not visible by the naked eye, such as restored lacunas and pentimenti, demonstrating the validity and complementarity of the proposed combined methodologies

Multispectral acquisition of large-sized pictorial surfaces

Multispectral acquisition of artworks has recently received considerable attention in the image processing community. Quite understandably, so far this attention has mainly focused on paintings, given their predominant role in museum collections. It is worth pointing out that the instrumentation and procedures used for acquiring regular paintings are not suited for the multispectral acquisition of large-sized painted surfaces such as frescoed halls and great paintings. Given the relevance of such artifacts, and their widespread presence in churches or historical buildings due to their social function, the problem of finding suitable techniques for their acquisition is certainly worth addressing. This paper focuses on multispectral acquisition of large-sized pictorial surfaces, systematically addressing the practical issues related to the acquisition equipment and procedure. Given the crucial role played by the illumination in this application, special attention is given to this issue. The proposed approach is supported by experimental results