Most of these techniques are applied to small areas of the painting either because they are destructive (that is, involve removing a sample from the work for analysis using polarized light microscopy or other techniques) or, if non-destructive, are too cumbersome and expensive to apply across the painting (e.g., air-path X-ray fluorescence spectroscopy, Raman spectroscopy). Subsequently, analytical methods, both destructive and non-destructive, are used in the classification and identification of pigments. When identifying and determining the spatial distribution of pigments in a work of art, conservators begin with a visual inspection of the artwork. The scientific examination of paintings often begins with the identification of the base set of pigments used by an artist. The method also provides the spatial distribution (maps) of materials, such as minerals and agricultural crops, across the imaged region. Spectral imaging (or Imaging Spectrometry), the collection of images in separate spectral bands in order to obtain reflection spectra, has been shown to be a powerful tool for geophysical remote sensing ( 1). The results show that multispectral imaging, either in numerous spectral bands from the visible to SWIR, or in a judicious selection of bands, can be a powerful tool to aid in pigment identification and distribution in paintings especially when combined with sample-based pigment identification methods such as X-ray fluorescence spectroscopy or analysis of cross-sections. The identification of the pigments was confirmed using air-path X-ray fluorescence spectroscopy and energy dispersive spectrometry. Multispectral imaging of two paintings by Vincent van Gogh provided reflectance spectra consistent with the presence of the blue pigments Prussian blue, cobalt blue and ultramarine and gave information on the distribution of the pigments in the works by utilizing spectral band ratio images and false color composites. The reflectance spectra of the test panels obtained using cameras were found to correlate to those obtained using the benchtop spectrometers. Two paintings known to contain a subset of the blue pigments listed above were imaged.
To test this, visible and infrared cameras were equipped with spectral band filters to allow collection of multispectral images of test panels and The large reflectance variation suggests the ability of broadband multispectral imaging (MSI) (< ~15 spectral bands, bandwidths of a few 100 to a few 10s of nm) to separate and support identification of these blue pigments in situ and to map their distribution. The measured spectra show that these blue pigments have large and varied reflectance in the near infrared (NIR, 0.7 to 1.0 microns) to shortwave infrared (SWIR, 1 to 2.5 microns) as compared to the visible spectral region. Toward this end, visible to shortwave infrared diffuse reflection spectra of the blue pigments in both powder and paint forms were collected to determine the optimal spectral region to discriminate among these pigments. The blue pigments considered are azurite, indigo, Prussian blue, lapis lazuli, cobalt blue, ultramarine, and thalo blue. In this paper spectral imaging in the reflective infrared (IR) spectral region (0.7 to 2.5 microns) is examined for its potential to discriminate and identify blue pigments in paintings. Hopefully, the conference will become the place where prominent scientists, worldwide experts and active researchers gather and meet to stimulate the communication of new innovative ideas and knowledge on new scientific methodologies, promote scientific exchange and discuss possibilities of further cooperation, networking and promotion of mobility of senior and young researchers and research students.Spectral imaging for conservators offers the promise of providing a non-destructive tool for the identification of artists’ materials in situ, as well as determining their spatial distribution in an artwork. The purpose of the conference is to bring together worldwide experts to give presentations on novel and advanced applications in their latest work in engineering, science and medicine to facilitate cross-fertilization among various key sectors of pure scientific and applied knowledge.
#FLETCHER METHOD MAP SERIES#
This is the 5th conference in a series organiz ed every three years since 2008.
The International Conference on Numerical Analysis and Optimization will be held in Sultan Qaboos University (SQU), Muscat, Oman on January 6-9, 2020.
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