Spectral Imaging and Archival Data in Analysing Madonna of the Rabbit Paintings by Manet and Titian

Abstract

A concise insight into the outputs provided by the latest prototype of visible-near infrared (Vis-NIR) multispectral scanner (National Research Council-National Institute of Optics, CNR-INO, Italy) is presented. The analytical data acquired on an oil painting Madonna of the Rabbit by É. Manet are described. In this work, the Vis-NIR was complemented with X-ray fluorescence (XRF) mapping for the chemical and spatial characterization of several pigments. The spatially registered Vis-NIR data facilitated their processing by spectral correlation mapping (SCM) and artificial neural network (ANN) algorithm, respectively, for pigment mapping and improved visibility of pentimenti and of underdrawing style. The data provided several key elements for the comparison with a homonymous original work by Titian studied within the ARCHive LABoratory (ARCHLAB) transnational access project.

Synchronized Hardware-Registered VIS-NIR Imaging Spectroscopy and 3D Sensing on a Fresco by Botticelli

“…While the first instruments for IR reflectography collected the radiation in a single, broad spectral range [1], the method gradually evolved, starting from the mid 1990's, into the multi/hyper spectral (MS/HS) modality, derived from Earth remote sensing techniques [2]. The great potential of MS/HS reflectance imaging spectroscopy (RIS) in the analysis of artworks has been recognized by the heritage science community, today including a large number of research groups active in this field [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. A detailed account of the evolution and progress, as well as of the fundamental physical principles of RIS and systems involved, is provided in a recent review [19].…”

“…The point-scanning approach, based on the detection of radiation reflected from painted surfaces by boustrophedon movement of a single photodiode, was introduced in the 1990's by a group of researchers at the National Institute of Optics (INO, now in the Italian National Research Council, INO-CNR) [8,18,20]. Such approach permits a very easy alignment and registration of geometrically-corrected images, at the cost of longer acquisition times.…”

Post-Processing of VIS, NIR, and SWIR Multispectral Images of Paintings. New Discovery on the The Drunkenness of Noah, Painted by Andrea Sacchi, Stored at Palazzo Chigi (Ariccia, Rome)

“…Traditional false-color photography has been comprehensively used as a guide for identification of pigments. The experimental procedure requires the combination of RGB color images and IR reflectogram, in which the image taken in the green range of the electromagnetic spectrum (centered at about 500 nm) replaces the blue image (B), the image taken in the red range (centered at about 600 nm) replaces the green image (G), and the IR reflectogram substitutes the red image (R) [16][17][18][19]. This approach is very useful to recognize pigments which have large differences in the IR absorbance, although they appear similar to the eye (i.e., lapis lazuli shows a red false-color with respect to the much less expensive azurite that looks blue [20]).…”

From remote sensing and machine learning to the history of the Silk Road: large scale material identification on wall paintings

“…Increasing awareness of conservation ethics is also limiting the analysis to mainly non-invasive techniques. This is also one of the reasons why 14 C dating could not be applied in this case.…”

“…However, automatic clustering methods on large number of image cubes have not been reported so far. Applications of clustering methods on spectral imaging data collected from paintings have been illustrated on a limited number of paintings for the identification of pigments [13][14][15][16] , binding media 17 and substrates 18 . These methods use the 'Spectral Hourglass Wizard' in ENVI 19 .…”