ABSTRACT When analysing a work of art, imaging data from multiple sources can be effectively inte... more ABSTRACT When analysing a work of art, imaging data from multiple sources can be effectively integrated and added to a 3D digital model, in order to form an improved multi-dimensional dataset. Herein we present the IR-colour reflectography, the UV fluorescence and the 3D microprofilometry diagnostic devices, developed at INOA, and we discuss the integration of 2D and 3D datasets, the former giving information of the surface (or nearly sub-surface) properties of a painting, the latter giving shape information of the surface itself.
Optics for Arts, Architecture, and Archaeology V, 2015
ABSTRACT Near-Infrared (NIR) reflectography is a well-established technique for painting diagnost... more ABSTRACT Near-Infrared (NIR) reflectography is a well-established technique for painting diagnostics, offering a fundamental contribution to the conservation of paintings. Since the '80s it has been routinely applied to study the execution technique of the author, as well as the presence of pentimenti, retouches, integrations or underdrawing. In the last decades IR reflectography has been extended to the visible (VIS) spectral range, providing information about the pigment composition. Up to now the multispectral analysis is still applied at an experimental level, as the processing of the image set is not straightforward. Rarely multispectral VIS-IR application has been applied to frescos, probably due to the lack, in most cases, of a scattering background. In this work we present the results provided by a multispectral scanning device based on single sensor acquisition, working in the 380-2500 nm spectral range, that is a laboratory prototype specifically built for research-grade imaging. The technique have been applied on a mock up simulating a mural painting substrate where an underdrawing, made of either carbon or iron-gall ink, was covered by different surface layers of limewash, the so-called scialbo.
Several drawings by Michelangelo Buonarroti (collection of Casa Buonarroti in Florence, Italy) we... more Several drawings by Michelangelo Buonarroti (collection of Casa Buonarroti in Florence, Italy) were xamined in-situ by non-invasive analytical techniques such as MultiSpectral Reflectography (MSR), Fiber Optic Reflectance Spectroscopy (FORS), Fourier Transform Infrared Spectroscopy (FT-IR), and X-Ray Fluorescence (XRF). The restricted material palette and the materials’ low concentrations present in drawings make the physicochemical survey challenging. Multispectral reflectography is a well-established technique for the non-invasive inspection of canvas and easel paintings. Especially in combination with other analytical methods it can provide information on the spatial distribution of constituents across the entire examined area providing essential information to historical and archaeometric research without taking any samples. For MSR a scanning instrument with single point measurements of reflectance was used to collect 30 spatially registered images at different wavelengths (400...
Summary  We describe an experiment which has been designed to measure both spatial and temporal f... more Summary  We describe an experiment which has been designed to measure both spatial and temporal features of turbulent thermal convection in a fluid layer heated from below. Specifically we have studied the dependence of the heat flowvs. the Rayleigh number, the thermal boundary layer profile, the temperature probability distribution function, the frequency and wave number power spectra. All the results have
Optics for Arts, Architecture, and Archaeology IV, 2013
ABSTRACT "Cleaning" is a process of carefully identifying the cause of any dete... more ABSTRACT "Cleaning" is a process of carefully identifying the cause of any deterioration or discolouration and then removing or treating these layers. The skill of the restorer is not only to understand the techniques and media used by the artist, but also to recognize what beauty lies beneath the veils of many years of neglect or adverse conditions. Surface cleaning is then one of the most important and sometimes controversial stages of the conservation process: it is an irreversible process that generally results in substantial physical changes of the object surface, raising thus a series of questions regarding aesthetics, the potential loss of historical information, and the ability to control the cleaning process adequately. Decisions have to be made regarding partial or complete removal of varnish: technical considerations include selection of a method that allows a great deal of control in the cleaning process, so that undesired layers can be removed without damaging the underlying ones by means of traditional cleaning methods, including mechanical or chemical removal. In this work we present a study of the optical properties of painting surfaces for the characterization of the cleaning process. Analyses were carried out by means of laser micro-profilometry and confocal microscopy. Measurements were carried out on a few paintings which are under repair at the Opificio delle Pietre Dure in Florence. Selected areas were surveyed with the two above mentioned techniques and results were correlated.
O3A: Optics for Arts, Architecture, and Archaeology III, 2011
ABSTRACT A variety of optical investigation methods applied to paintings are, by now, an integral... more ABSTRACT A variety of optical investigation methods applied to paintings are, by now, an integral part of the repair process, both to plan the restoration intervention and to monitor its various phases. Among them infrared reflectography in wide-band modality is traditionally employed in non-invasive diagnostics of ancient paintings to reveal features underlying the pictorial layer thanks to transparency characteristics to NIR radiation of most of the materials composing the paints. This technique was improved with the introduction of the multi-spectral modality that consists in acquiring the radiation back scattered from the painting into narrow spectral bands. The technology, widely used in remote sensing applications such as satellite or radar imaging, has only recently gained importance in the field of artwork conservation thanks to the varied reflectance and transmittance of pigments over this spectral region. In this work we present a scanning device for multi-NIR spectral imaging of paintings, based on contact-less and singlepoint measurement of the reflectance of painted surfaces. The back-scattered radiation is focused on square-shaped fiber bundle that carries the light to an array of 16 photodiodes equipped with pass-band filters so to cover the NIR spectral range from 900 to 2500 nm. In particular, we describe the last instrument upgrade that consists in the addition of an autofocus system that keeps the optical head perfectly focused during the scanning. The output of the autofocus system can be used as a raw map of the painting shape.
The aim of this work has been to show how 3D scanning techniques can provide new, useful and powe... more The aim of this work has been to show how 3D scanning techniques can provide new, useful and powerful tools to the restorers. In fact, 3D models are able both to monitor the restoration process: eg variations of the shape of a statue, due for example to the removal of plaster and wooden parts, and to keep trace of the modifications that take place during the conservation operations: eg the polishing of a corroded bronze surface. The focus of this project was to acquire 3D data with different resolutions, with specially designed acquisition means, and ...
This work, aimed at quantifying the morphological variations induced by laser cleaning on stone m... more This work, aimed at quantifying the morphological variations induced by laser cleaning on stone materials, represents a very first attempt for a new quantitative means to reveal changes in stone surfaces. It is a three-dimensional survey carried out by means of laser micro-profilometry and completed by statistical data processing. The acquisition and successive computation is performed on small selected areas
19th Congress of the International Commission for Optics: Optics for the Quality of Life, 2003
The aim of this work is to show how 3D techniques can be used to integrate standard diagnostics, ... more The aim of this work is to show how 3D techniques can be used to integrate standard diagnostics, adding useful and powerful tools for the restorers. Our plan is to assemble a few complete 3D digital models of a bronze statue, the Minerva of Arezzo, either before or during its repair, to keep trace of every significant modification occurring in
ABSTRACT The knowledge of the shape of an artwork is an important element for its study and conse... more ABSTRACT The knowledge of the shape of an artwork is an important element for its study and conservation. When dealing with a stone statue, roughness measurement is a very useful contribution to document its surface conditions, to assess either changes due to restoration intervention or surface decays due to weathering agents, and to monitor its time-evolution in terms of shape variations. In this work we present the preliminary results of the statistical analysis carried out on acquired data relative to six areas of the Michelangelo’s David marble statue, representative of differently degraded surfaces. Determination of the roughness and its relative characteristic wavelength is shown.
This work is intended to show the results of a few architectural and archaeological surveys reali... more This work is intended to show the results of a few architectural and archaeological surveys realized by means of a 3D scanning device, based on TOF (Time-Of-Flight) technology. The instrument was set up by the Art Diagnostic Group of the National Institute for Applied Optics (INOA) and it is composed by a high precision scanning system equipped with a commercial
We describe the application of 2D and 3D data acquisition and mutual registration to the conserva... more We describe the application of 2D and 3D data acquisition and mutual registration to the conservation of paintings. RGB color image acquisition, IR and UV fluorescence imaging, together with the more recent hyperspectral imaging (32 bands) are among the most useful techniques in this field. They generally are meant to provide information on the painting materials, on the employed techniques
A quantitative morphological analysis of archaeological objects represents an important element f... more A quantitative morphological analysis of archaeological objects represents an important element for historical evaluations, artistic studies and conservation projects. At present, a variety of contact instruments for high-resolution surface survey is available on the market, but because of their invasivity they are not well received in the field of artwork conservation. On the contrary, optical testing techniques have seen a
O3A: Optics for Arts, Architecture, and Archaeology, 2007
The quantitative morphological analysis of a painting surface allows to evidence form defects and... more The quantitative morphological analysis of a painting surface allows to evidence form defects and to study, thus, their influence on the stability of the paint and preparatory layers, as well as of the support. Therefore a three-dimensional survey can be very useful in planning the restoration intervention of a painting. In this work we present the results of the surface
3D measurement and modelling have been traditionally applied to statues, buildings, archeological... more 3D measurement and modelling have been traditionally applied to statues, buildings, archeological sites or similar large structures, but rarely to paintings. Recently, however, 3D measurements have been performed successfully also on easel paintings, allowing to detect and document the painting's surface. We used 3D models to integrate the results of various 2D imaging techniques on a common reference frame. These
O3A: Optics for Arts, Architecture, and Archaeology, 2007
In this paper we present a scanning device for multispectral imaging of paintings in the 380-800 ... more In this paper we present a scanning device for multispectral imaging of paintings in the 380-800 nm spectral region; the system is based on a spectrophotometer for contact-less single-point measurements of the spectral reflectance with 10 nm resolution. Two orthogonal XY translation stages allow to scan up to 1,5 m2 with spatial resolution up to 8 dots/mm. As an application
ABSTRACT When analysing a work of art, imaging data from multiple sources can be effectively inte... more ABSTRACT When analysing a work of art, imaging data from multiple sources can be effectively integrated and added to a 3D digital model, in order to form an improved multi-dimensional dataset. Herein we present the IR-colour reflectography, the UV fluorescence and the 3D microprofilometry diagnostic devices, developed at INOA, and we discuss the integration of 2D and 3D datasets, the former giving information of the surface (or nearly sub-surface) properties of a painting, the latter giving shape information of the surface itself.
Optics for Arts, Architecture, and Archaeology V, 2015
ABSTRACT Near-Infrared (NIR) reflectography is a well-established technique for painting diagnost... more ABSTRACT Near-Infrared (NIR) reflectography is a well-established technique for painting diagnostics, offering a fundamental contribution to the conservation of paintings. Since the '80s it has been routinely applied to study the execution technique of the author, as well as the presence of pentimenti, retouches, integrations or underdrawing. In the last decades IR reflectography has been extended to the visible (VIS) spectral range, providing information about the pigment composition. Up to now the multispectral analysis is still applied at an experimental level, as the processing of the image set is not straightforward. Rarely multispectral VIS-IR application has been applied to frescos, probably due to the lack, in most cases, of a scattering background. In this work we present the results provided by a multispectral scanning device based on single sensor acquisition, working in the 380-2500 nm spectral range, that is a laboratory prototype specifically built for research-grade imaging. The technique have been applied on a mock up simulating a mural painting substrate where an underdrawing, made of either carbon or iron-gall ink, was covered by different surface layers of limewash, the so-called scialbo.
Several drawings by Michelangelo Buonarroti (collection of Casa Buonarroti in Florence, Italy) we... more Several drawings by Michelangelo Buonarroti (collection of Casa Buonarroti in Florence, Italy) were xamined in-situ by non-invasive analytical techniques such as MultiSpectral Reflectography (MSR), Fiber Optic Reflectance Spectroscopy (FORS), Fourier Transform Infrared Spectroscopy (FT-IR), and X-Ray Fluorescence (XRF). The restricted material palette and the materials’ low concentrations present in drawings make the physicochemical survey challenging. Multispectral reflectography is a well-established technique for the non-invasive inspection of canvas and easel paintings. Especially in combination with other analytical methods it can provide information on the spatial distribution of constituents across the entire examined area providing essential information to historical and archaeometric research without taking any samples. For MSR a scanning instrument with single point measurements of reflectance was used to collect 30 spatially registered images at different wavelengths (400...
Summary  We describe an experiment which has been designed to measure both spatial and temporal f... more Summary  We describe an experiment which has been designed to measure both spatial and temporal features of turbulent thermal convection in a fluid layer heated from below. Specifically we have studied the dependence of the heat flowvs. the Rayleigh number, the thermal boundary layer profile, the temperature probability distribution function, the frequency and wave number power spectra. All the results have
Optics for Arts, Architecture, and Archaeology IV, 2013
ABSTRACT "Cleaning" is a process of carefully identifying the cause of any dete... more ABSTRACT "Cleaning" is a process of carefully identifying the cause of any deterioration or discolouration and then removing or treating these layers. The skill of the restorer is not only to understand the techniques and media used by the artist, but also to recognize what beauty lies beneath the veils of many years of neglect or adverse conditions. Surface cleaning is then one of the most important and sometimes controversial stages of the conservation process: it is an irreversible process that generally results in substantial physical changes of the object surface, raising thus a series of questions regarding aesthetics, the potential loss of historical information, and the ability to control the cleaning process adequately. Decisions have to be made regarding partial or complete removal of varnish: technical considerations include selection of a method that allows a great deal of control in the cleaning process, so that undesired layers can be removed without damaging the underlying ones by means of traditional cleaning methods, including mechanical or chemical removal. In this work we present a study of the optical properties of painting surfaces for the characterization of the cleaning process. Analyses were carried out by means of laser micro-profilometry and confocal microscopy. Measurements were carried out on a few paintings which are under repair at the Opificio delle Pietre Dure in Florence. Selected areas were surveyed with the two above mentioned techniques and results were correlated.
O3A: Optics for Arts, Architecture, and Archaeology III, 2011
ABSTRACT A variety of optical investigation methods applied to paintings are, by now, an integral... more ABSTRACT A variety of optical investigation methods applied to paintings are, by now, an integral part of the repair process, both to plan the restoration intervention and to monitor its various phases. Among them infrared reflectography in wide-band modality is traditionally employed in non-invasive diagnostics of ancient paintings to reveal features underlying the pictorial layer thanks to transparency characteristics to NIR radiation of most of the materials composing the paints. This technique was improved with the introduction of the multi-spectral modality that consists in acquiring the radiation back scattered from the painting into narrow spectral bands. The technology, widely used in remote sensing applications such as satellite or radar imaging, has only recently gained importance in the field of artwork conservation thanks to the varied reflectance and transmittance of pigments over this spectral region. In this work we present a scanning device for multi-NIR spectral imaging of paintings, based on contact-less and singlepoint measurement of the reflectance of painted surfaces. The back-scattered radiation is focused on square-shaped fiber bundle that carries the light to an array of 16 photodiodes equipped with pass-band filters so to cover the NIR spectral range from 900 to 2500 nm. In particular, we describe the last instrument upgrade that consists in the addition of an autofocus system that keeps the optical head perfectly focused during the scanning. The output of the autofocus system can be used as a raw map of the painting shape.
The aim of this work has been to show how 3D scanning techniques can provide new, useful and powe... more The aim of this work has been to show how 3D scanning techniques can provide new, useful and powerful tools to the restorers. In fact, 3D models are able both to monitor the restoration process: eg variations of the shape of a statue, due for example to the removal of plaster and wooden parts, and to keep trace of the modifications that take place during the conservation operations: eg the polishing of a corroded bronze surface. The focus of this project was to acquire 3D data with different resolutions, with specially designed acquisition means, and ...
This work, aimed at quantifying the morphological variations induced by laser cleaning on stone m... more This work, aimed at quantifying the morphological variations induced by laser cleaning on stone materials, represents a very first attempt for a new quantitative means to reveal changes in stone surfaces. It is a three-dimensional survey carried out by means of laser micro-profilometry and completed by statistical data processing. The acquisition and successive computation is performed on small selected areas
19th Congress of the International Commission for Optics: Optics for the Quality of Life, 2003
The aim of this work is to show how 3D techniques can be used to integrate standard diagnostics, ... more The aim of this work is to show how 3D techniques can be used to integrate standard diagnostics, adding useful and powerful tools for the restorers. Our plan is to assemble a few complete 3D digital models of a bronze statue, the Minerva of Arezzo, either before or during its repair, to keep trace of every significant modification occurring in
ABSTRACT The knowledge of the shape of an artwork is an important element for its study and conse... more ABSTRACT The knowledge of the shape of an artwork is an important element for its study and conservation. When dealing with a stone statue, roughness measurement is a very useful contribution to document its surface conditions, to assess either changes due to restoration intervention or surface decays due to weathering agents, and to monitor its time-evolution in terms of shape variations. In this work we present the preliminary results of the statistical analysis carried out on acquired data relative to six areas of the Michelangelo’s David marble statue, representative of differently degraded surfaces. Determination of the roughness and its relative characteristic wavelength is shown.
This work is intended to show the results of a few architectural and archaeological surveys reali... more This work is intended to show the results of a few architectural and archaeological surveys realized by means of a 3D scanning device, based on TOF (Time-Of-Flight) technology. The instrument was set up by the Art Diagnostic Group of the National Institute for Applied Optics (INOA) and it is composed by a high precision scanning system equipped with a commercial
We describe the application of 2D and 3D data acquisition and mutual registration to the conserva... more We describe the application of 2D and 3D data acquisition and mutual registration to the conservation of paintings. RGB color image acquisition, IR and UV fluorescence imaging, together with the more recent hyperspectral imaging (32 bands) are among the most useful techniques in this field. They generally are meant to provide information on the painting materials, on the employed techniques
A quantitative morphological analysis of archaeological objects represents an important element f... more A quantitative morphological analysis of archaeological objects represents an important element for historical evaluations, artistic studies and conservation projects. At present, a variety of contact instruments for high-resolution surface survey is available on the market, but because of their invasivity they are not well received in the field of artwork conservation. On the contrary, optical testing techniques have seen a
O3A: Optics for Arts, Architecture, and Archaeology, 2007
The quantitative morphological analysis of a painting surface allows to evidence form defects and... more The quantitative morphological analysis of a painting surface allows to evidence form defects and to study, thus, their influence on the stability of the paint and preparatory layers, as well as of the support. Therefore a three-dimensional survey can be very useful in planning the restoration intervention of a painting. In this work we present the results of the surface
3D measurement and modelling have been traditionally applied to statues, buildings, archeological... more 3D measurement and modelling have been traditionally applied to statues, buildings, archeological sites or similar large structures, but rarely to paintings. Recently, however, 3D measurements have been performed successfully also on easel paintings, allowing to detect and document the painting's surface. We used 3D models to integrate the results of various 2D imaging techniques on a common reference frame. These
O3A: Optics for Arts, Architecture, and Archaeology, 2007
In this paper we present a scanning device for multispectral imaging of paintings in the 380-800 ... more In this paper we present a scanning device for multispectral imaging of paintings in the 380-800 nm spectral region; the system is based on a spectrophotometer for contact-less single-point measurements of the spectral reflectance with 10 nm resolution. Two orthogonal XY translation stages allow to scan up to 1,5 m2 with spatial resolution up to 8 dots/mm. As an application
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Papers by Enrico Pampaloni