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Recent progress in the realm of imaging technologies has swiftly disseminated fresh methodologies for representing objects, broadening the horizons for scholars such as art historians, archaeologists, conservators, and conservation scientists. Reflectance Transformation Imaging (RTI) and three-dimensional (3D) modeling via Structure from Motion (SfM) have rapidly gained popularity and are being employed by a wide range of users, expanding the possibilities for understanding objects of material cultural heritage from different perspectives. This paper explores the outcomes achieved through the application of these techniques to gain deeper insights into the surface of a bas-relief within a confined space. This methodology enhanced our understanding of the original sandstone surfaces of the bas-relief by integrating RTI and 3D visualization, thereby acquiring a novel investigative tool with enhanced illumination possibilities. A data fusion approach is proposed using photogrammetry to produce a Virtual RTI (V-RTI). In the case study reported in this paper, focusing on one inner wall of the chapel of Ellesiya at the Museo Egizio of Turin, V-RTI was employed to obtain useful surface information in a context where conventional RTI would have been impossible to achieve. Finally, the study compares the different techniques through direct qualitative and quantitative analysis, highlighting possible future developments from both instrumental and methodological points of view. [ABSTRACT FROM AUTHOR]

A limestone relief fragment with a figure in a winged disk from the fifth-century BCE Hall of 100 Columns at Persepolis in southwestern Iran that entered the Harvard Art Museums' collections in 1943 preserves significant traces of its original coloration and has played a key role in the rediscovery of polychromy at the Achaemenid Persian capital. After tracing the fragment's journey to Cambridge, MA, this article presents the results of recent technical studies of its pigment remains, including visible light-induced infrared luminescence (VIL) imaging, X-ray fluorescence (XRF) spectroscopy, and the analysis of micro samples by Raman spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and polarizing light microscopy (PLM). The new scientific data is compared to the findings of ongoing investigations of polychromies at Persepolis and other Achaemenid Persian sites and evaluated for the information it can and cannot provide on the original appearance of the figure in the winged disk, likely the Zoroastrian god Ahuramazda. The article reviews past attempts at reconstructing the relief's coloration and the assumptions that guided them, recounts the experience of creating a tangible three-dimensional color reconstruction for an exhibition, and concludes with some general thoughts on the valuation of colorfulness. [ABSTRACT FROM AUTHOR]

This paper introduces the Watermark Imaging System (WImSy) which can be used to photograph, document, and study sheets of paper. The WImSy provides surface images, raking light images, and transmitted light images of the paper, all in perfect alignment. We develop algorithms that exploit this alignment by combining several images together in a process that mimics both the “surface image removal” technique and the method of “high dynamic range” photographs. An improved optimization criterion and an automatic parameter selection procedure streamline the process and make it practical for art historians and conservators to extract the relevant information to study watermarks. The effectiveness of the method is demonstrated in several experiments on images taken with the WImSy at the Metropolitan Museum of Art in New York and at the Getty Museum in Los Angeles, and the results are compared with manually optimized images.

This paper introduces the Watermark Imaging System (WImSy) which can be used to photograph, document, and study sheets of paper. The WImSy provides surface images, raking light images, and transmitted light images of the paper, all in perfect alignment. We develop algorithms that exploit this alignment by combining several images together in a process that mimics both the "surface image removal" technique and the method of "high dynamic range" photographs. An improved optimization criterion and an automatic parameter selection procedure streamline the process and make it practical for art historians and conservators to extract the relevant information to study watermarks. The effectiveness of the method is demonstrated in several experiments on images taken with the WImSy at the Metropolitan Museum of Art in New York and at the Getty Museum in Los Angeles, and the results are compared with manually optimized images. [ABSTRACT FROM AUTHOR]

This paper provides the results of a 3D photogrammetric survey of the apsidal conch of St. Panfilo Church in Tornimparte (L'Aquila, Italy). The images were acquired and then processed in order to obtain a three-dimensional model available on Sketchfab platform. The five panels and the vault of the apsidal conch were exported from the 3D model as orthomosaics and then imported into CAD software for the mapping of the main degradation phenomena. The examined surface was almost entirely covered by mural painting and restoring mortars, the latter mainly located in the lower part of the apsidal conch. The whole surface of the apsidal conch was also examined by means of raking light that enabled highlighting of conservation problems and the presence of incision marks and giornata/pontate boundaries indicating the use of the fresco painting technique. Several degradation phenomena, attributable both to the executive technique of wall painting and the microclimate conditions, could be observed. According to the overlapping of weathering forms and the material involved, most of the examined surfaces exhibited moderate to very severe degradation. [ABSTRACT FROM AUTHOR]

This paper provides the results of a 3D photogrammetric survey of the apsidal conch of St. Panfilo Church in Tornimparte (L’Aquila, Italy). The images were acquired and then processed in order to obtain a three-dimensional model available on Sketchfab platform. The five panels and the vault of the apsidal conch were exported from the 3D model as orthomosaics and then imported into CAD software for the mapping of the main degradation phenomena. The examined surface was almost entirely covered by mural painting and restoring mortars, the latter mainly located in the lower part of the apsidal conch. The whole surface of the apsidal conch was also examined by means of raking light that enabled highlighting of conservation problems and the presence of incision marks and giornata/pontate boundaries indicating the use of the fresco painting technique. Several degradation phenomena, attributable both to the executive technique of wall painting and the microclimate conditions, could be observed. According to the overlapping of weathering forms and the material involved, most of the examined surfaces exhibited moderate to very severe degradation.

The focus of this paper is to reveal unknown features and to obtain still more information on technology of wood working used on the black shrine-shaped boxes from Tutankhamen collection. Moreover, the authors were significantly interested in identification of the wood species and shed lit on the reflection of The sudden death of the young king, the value of wood and its relative scarcity, not only in ingenious shrines construction methods and the incorporation of many fragments of timber, but also in the presence numerous pieces that show clear evidence of reuse from earlier objects. Patching, even for the royal wood workings, with another piece of wood secured by dowels and white pastes was one option and knots holes were sometimes drilled out and filled with plugs. The botanical species of the wood samples were identified by observing the thin sections under an optical transmission light microscope; technology of wood working were examined by visible imaging and raking light along with 3D software. The results revealed that cedar of Lebanon (Cedrus libani) and sycamore fig (Ficus sycomorus) had been used for making the shrines' boards and sleds while tamarisk (Tamarix sp.), Turkey oak (Quercus cerris L.), and Sidder (nabk) (Zizyphus spina Christi) used for making wooden dowels. Wooden pegs used to collect the shrine boards, roof and cornice together while the wooden joint of through mortise and tenon was used to collect the body of the shrine to the sled. The raking light was effective in revealing the tools marks. [ABSTRACT FROM AUTHOR]

The main goal of this work was the non-destructive testing (NDT) of an ancient fresco (15th century) preserved in the Santa Maria di Collemaggio Church (L’Aquila, Italy) and damaged after the 2009 earthquake. Active infrared thermography (IRT), near-infrared (NIR) reflectography and ultraviolet imaging (UV) were used. In addition, the state of the fresco prior to the earthquake was analyzed by electronic speckle pattern interferometry (ESPI), digital speckle correlation (DSC), raking light, tap, and chemical NDT techniques. The use of these techniques was important for the monitoring of new damages and for a comparison between the results over the years. Square heating thermography (SHT) data were processed using principal component thermography (PCT) and pulsed phase thermography (PPT) algorithms, in order to improve the defects’ signature and to reduce the impact of non-uniform heating and emissivity variations due to the painting’s pigments. A multi-analysis approach, segmentation operators and a specific data correlation method emphasize the overall study of the fresco. Furthermore, the facade and the high altar area were inspected by passive thermography and ground-penetrating radar (GPR), respectively. In the present case, the combined use of NDT techniques was useful to fill in the gaps in the construction history of the building. [ABSTRACT FROM PUBLISHER]

Conservators at Universitat Politécnica de Valencia, Spain, explore the advantages and potential applications of Reflectance Transformation Imaging (RTI) as an innovative instrument for the documentation and analysis of texture of cultural objects undergoing conservation treatments. A computational photography technique, RTI creates highly accurate and interactive images, where objects can be illuminated from different directions and through a variety of filters to emphasize their surface texture and color. RTI was implemented to try the technique effectiveness for performing detailed examination and diagnostics on a variety of materials, including paintings, works on paper, wooden sculptures, metals, and stone. Resulting images yielded new and valuable information in the identification of manufacturing techniques and assessments of surface condition that were not previously recognized through direct examination or any other photographic techniques. RTI also proved highly effective for detailed documentation of painting and paper objects before and after treatments, helping to assess many subtle changes on pictorial layers and paper supports caused by conservation processes. RTI is an affordable and accessible resource which would be beneficial for to both cultural institutions and individual conservators for the interpretation and evaluation of cultural heritage. [ABSTRACT FROM AUTHOR]