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L’impiego delle più sofisticate tecniche di rilevamento delle antiche pitture murali, mediante imaging multispettrali con analisi multivariate hanno consentito la restituzione e l’elaborazione grafica virtuale della decorazione pittorica murale della Tomba dei Demoni Azzurri (450–430 a.C.) della necropoli di Monterozzi, a Tarquinia (Viterbo, alto Lazio). È stato così possibile analizzare il programma iconografico originariamente concepito per la tomba, che comprendeva scene di caccia cui partecipavano prede autoctone e predatori esotici fra cui alcuni felidi vicino-orientali e/o nordafricani il cui uso come ausiliari venatori sarebbe qui documentato per la prima volta. The use of the most sophisticated techniques for the detection of ancient wall paintings, by means of multispectral imaging with multivariate analysis, has enabled the restitution and virtual graphic elaboration of the pictorial wall decoration of the Etruscan Tomba dei Demoni Azzurri (450-430 BCE) of the Monterozzi necropolis in Tarquinia (Viterbo, upper Latium). It was thus possible to analyse the iconographic programme originally conceived for the tomb, which included hunting scenes involving indigenous prey and exotic predators, including Near Eastern and/or North African felids whose use as hunting auxiliaries is documented here for the first time.

In this article, we present a new method for the analysis of visible/Infrared multispectral sets producing chromatically faithful false-color images, which maintain a good readability of the information contained in the non-visible Infrared band. Examples of the application of this technique are given on the multispectral images acquired on the Pietà of Santa Croce of Agnolo Bronzino (1569, Florence) and on the analysis and visualization of the multispectral data obtained on Etruscan mural paintings ( Tomb of the Monkey , Siena, Italy, V century B.C.). The fidelity of the chromatic appearance of the resulting images, coupled to the effective visualization of the information contained in the Infrared band, opens interesting perspectives for the use of the method for visualization and presentation of the results of multispectral analysis in Cultural Heritage diffusion, research, and diagnostics.

New approaches in the application of multispectral imaging to the recovery of archeological wall paintings are presented, based on statistical techniques and on a novel method of image treatment (Chromatic Derivative Imaging – ChromaDI) which offers a way of embedding information coming from four spectral bands into a standard RGB image. The methods are applied to some wall paintings from the Tomb of the Monkey, an Etruscan tomb in the necropolis of Poggio Renzo, near the city of Chiusi (Siena), Italy, dated around 480-470 BC. It is shown that the techniques described are able to highlight and enhance a number of details that cannot be perceived in either any of the original channel images or any single processed output channel.

In this paper, we discuss the application of different Blind Source Separation algorithms for enhancing hidden patterns in paintings and retrieving the information there contained. A series of images was taken at different wavelengths of a painting of an unknown artist, which evidenced the presence of hidden text. The analysis of the single images did not allow retrieving the information contained in the hidden text. The application of Blind Source Separation algorithms on the other hand allowed the enhancement of the hidden pattern; in particular, the orthogonalization algorithm proved to be fast and highly efficient. Good results were also obtained applying the same algorithm on a subset of spectral images (two out of four available), demonstrating the possibility of further reducing the computational load of the algorithm while retaining a good readability of the retrieved text.

We report about a recent implementation of the INOA scanning device for infrared reflectography. The realization of a new optical head allows the simultaneous acquisition of the reflectogram and the colour image of the painting, perfectly superimposing. We show two example of application of this new device in the analysis of two ancient paintings: the Madonna con Bambino e Santi by Matteo di Giovanni and the La Tempesta by Giorgione.

Imaging techniques are widely used for the diagnostics of paintings. The results, collected by applying various imaging techniques are generally compared by the art historian who studies the object. These 2D data can be effectively integrated to form a multi-dimensional dataset, and added to a 3D digital model of the painting, thus creating a complete package of information about the opera. In this work we present some examples of applications of data integration with measurements performed on some important panel paintings. The imaging analysis was carried out by applying techniques such as infrared reflectography, colour and false colour imaging and ultraviolet fluorescence. The IR reflectogram, the false colour and the colour image are simultaneously acquired with a scanning device characterized by a high resolution (16 dots/mm2), a high tonal dynamic and point-to-point correspondence between these three images. A multi-spectral device, based on a high-resolution CCD camera, is used for UV fluorescence. The 3D relief was obtained by means of scanning micro-profilometry with a quota resolution of about 1 micron. The integration of the 3D model with the results given by several imaging techniques greatly increases the information and it eases the analysis of the painting under investigation.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The realization of an accurate 3D model of a building, a piece of architecture or a terrain has been a prerogative of the photogrammetric systems for a long time. However, recent developments in opto-electronic technology and 3D analysis software made the production of 3D models by laser scanning a practical proposition. The main advantages of laser scanners are accuracy and speed, allowing, thus, the collecting of data on a dense sampling of the object. For many architectural and industrial applications it is important to integrate the data acquired with different instruments, but a problem met with many commercial systems is the lack of compatibility with classic survey methodologies. Moreover, superimposition of results from different techniques is possible only if the output is metrically correct. This work is aimed at showing the results of some architectural and archaeological surveys realized by means of a 3D scanning device, based on the Time-Of-Flight (TOF) technology. The instrument, devoted to architectural applications in the Cultural Heritage field, was set up in order to provide the characteristics of reliability and compatibility to other systems. Such a device is composed by a high precision scanning system equipped with a commercial low-cost distance-meter.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Infrared reflectography is a prominent optical technique for non-destructive diagnostics of paintings, which allows the visualisation of details hidden by the paint layers, because of their transparency characteristics to IR radiation. High-resolution reflectography was introduced around the end of the 80s by the Istituto Nazionale di Ottica Applicata , where a prototype of an innovative scanner device was developed. This technique was recently improved with the introduction of a new optical head, able to acquire simultaneously the reflectogram and the colour image, perfectly superimposing. The technical characteristics of the IR-colour scanner guarantee: a high spatial resolution (16 points/mm2), a high tonal dynamics (thousands of grey levels), a uniform lighting of the scanned area and the punctual superimposition of the colour and IR images. Moreover we can print distortion-free reflectograms, false-colour and colour images of paintings on a 1:1 scale. The quality of the acquired reflectogram is presently higher than that obtainable with any traditional detection system, like CCD or Vidicon cameras. The point-by-point comparison between the reflectogram and the colour image of the painting, along with digital processing of the recorded images, open new possibilities for the analysis of the reflectogram. Some examples of application to the study of ancient paintings are shown.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The knowledge of the shape of an artwork is an important element for its study and conservation. When dealing with a 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 wearing 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.