Statement on Spectroscopic Imaging in Art Conservation: A New Tool for Materials Investigations

http://leoalmanac.org/journal/Vol_10/lea_v10_n09.tx

Spectroscopic Imaging in Art Conservation: A New Tool for Materials Investigations

https://www.mitpressjournals.org/doi/10.1162/00240940332225873

“The Man with Three Feet” in Pieter Bruegel the Elder’s Peasant Wedding

Lorsque Bruegel a peint Le Repas de Noces Paysannes, il a conçu le groupe des trois serviteurs au premier plan de telle façon qu’une illusion visuelle d’un homme doté de trois pieds a été créée, une anomalie qui a causé la confusion autant pour les copistes que pour les chercheurs. Nous présentons ici une explication de ce problème, que nous appuyons par des photographies d’un tableau vivant de l’action présentée et d’une simulation numérique. L’ambiguité de l’image crée une illusion Poggendorf qui éveille l’attention du spectateur et provoque un stimuli quant à la perception du mouvement dans cette oeuvre

Quotation : Re-presenting History

Essays by Madill provide an introduction and analysis of the work of seven artists employing photo-related media to address prevailing notions of authenticity, quality, and individuality. Hutcheon qualifies nostalgic and ironic citation, highlighting the subjective nature of interpretation; a uniquely formatted text by Majzels interprets the work. Biographical notes. 39 bibl. ref

Near infrared spectroscopic reflectance imaging : a new tool in art conservation

The application of infrared spectroscopic imaging to non-destructive examination of works of art is described. Its advantages over infrared photography and reflectography are discussed, in particular its ability to provide spectroscopic information, which potentially allows identification of pigments, binders, and other materials. Near-infrared spectra of a selection of brown and black pigments are presented. Results are given of the application of infrared spectroscopic imaging to two works of art in different media: an ink drawing and an oil painting.Peer reviewed: YesNRC publication: Ye

Near-infrared spectroscopic imaging in art conservation : investigation of drawing constituents

The remote-sensing technique of spectroscopic imaging has been adapted to the non-destructive examination of works of art. The principle of near-infrared re\ufb02ectance spectroscopic imaging is explained, and our instrumentation for art examination described. The technique allows the art materials to be distinguished by their composition, and under-drawings revealed. The initial results indicate that even over limited wavelength ranges (650\u20131040 nm) and with relatively coarse spectral resolution (10 nm) a number of pigments can be distinguished on the basis of variations in spectral properties such as spectral slope and the presence or absence of absorption bands. Software adapted from the remote-sensing image-processing \ufb01eld has been used to successfully map areas of different brown and black pigments across a drawing. Non-destructive identi\ufb01cation of pigments can be used to address issues of attribution, age dating, and conservation. An additional advantage of this technique is that it can be performed off-site using portable instrumentation, and under relatively benign lighting conditions. The technique has been applied to the examination of a 15th-century drawing, Untitled (The Holy Trinity), in the collection of the Winnipeg Art Gallery. Multivariate image analysis produced a set of principal component (PC) images highlighting different materials\u2019 aspects of the drawing. A color composite image produced from the PC images provided a direct visualization of the compositional characteristics of the work. Features of the under-drawing have been exposed, and its material tentatively identi\ufb01ed as charcoal, by comparison with reference data.Peer reviewed: YesNRC publication: Ye

Near infrared spectroscopic reflectance imaging : supervised versus unsupervised analysis using an art conservation application

Near-IR spectroscopic imaging was used to analyze the remnants of a work of art, a 16th century drawing, attributed to the School of Pieter Bruegel the Elder, which had been significantly altered during a cleaning attempt. Using a combination of a CCD camera and a liquid crystal tunable filter (LCTF), near-IR spectroscopic images (650-1050 nm) were collected from the drawing and from a test sample composed of four substances with differing near-IR spectra deposited on a whiteboard surface. Both supervised and unsupervised classification methodologies (linear discriminant analysis (LDA) and fuzzy C-means (FCM) clustering, respectively) were used to analyze the data. FCM clustering, in combination with several spectral normalization routines, proved an excellent data exploration method for the test sample. LDA gave consistently clearer results than the FCM methods, but required a priori knowledge of the spectral properties of the sample, provided, in this case, by the FCM analysis. LDA of the spectroscopic image of the work of art revealed clearly and for the first time the location of regions of the drawing where faint traces of ink residue remained.Peer reviewed: YesNRC publication: Ye