Georgios Karagiannis

Panselinos’ Byzantine wall paintings in the Protaton Church, Mount Athos, Greece: a technical examination

Abstract The sole surviving fresco paintings of Manuel Panselinos (13th century AD), one of the most celebrated Greek iconographers of the Byzantine era, are located in the Protaton Church (10th century AD) on Mount Athos, Greece. This paper presents an examination and technical analysis of 15 representative thematic scenes, covering an area of approximately 65 m 2 , from these monumental works of art. The following exhaustive study and documentation of both the original and the subsequently restored areas of the wall paintings were made possible by using various imaging techniques, including visible and ultra-violet photography, infrared reflectography, colour measurements and representation. The chemical identification of the pigments, binders and layer stratigraphy was achieved through the use of visible and ultra-violet fluorescence microscopy, micro-Raman spectroscopy, Fourier transform μspectroscopy (μFTIR), X-ray diffraction (XRD), and scanning electron microscopy with energy dispersive analysis (SEM-EDS) and electron probe microanalysis (EPMA). A collaborative analysis, its results demonstrate that the paintings were executed in both the true fresco and lime-painting techniques. They have also established Panselinos’ choice of materials and colour palette. We believe this study to be an important and necessary prerequisite for the future preservation and restoration of these unique frescoes.

Three-Dimensional Nondestructive “Sampling” of Art Objects Using Acoustic Microscopy and Time–Frequency Analysis

The microsampling destructions, which are caused by the sampling procedures of analytical spectroscopic methods, are, in most cases, not permitted to art objects, which are extremely valuable, rare, and fragile. Consequently, the development of nondestructive analysis techniques becomes a necessity. In this paper, we present a technique and method for the nondestructive identification of the stratigraphic structure of the paint layers of art objects. Using acoustic microscopy, in combination with time-frequency representations, the continuous or discrete wavelet transform, or the Hilbert-Huang transform, the depth profile of the stratigraphy is determined.

Eikonomia-An Integrated Semantically Aware Tool for Description and Retrieval of Byzantine Art Information

Semantic annotation and querying is currently applied on a number of versatile disciplines, providing the added-value of such an approach and, consequently the need for more elaborate - either case-specific or generic - tools. In this context, we have developed Eikonomia: an integrated semantically-aware tool for the description and retrieval of Byzantine artwork Information. Following the needs of the ORMYLIA Art Diagnosis Center for adding semantics to their legacy data, an ontology describing Byzantine artwork based on CIDOC-CRM, along with the interfaces for synchronization to and from the existing RDBMS have been implemented. This ontology has been linked to a reasoning tool, while a dynamic interface for the automated creation of semantic queries in SPARQL was developed. Finally, all the appropriate interfaces were instantiated, in order to allow easy ontology manipulation, query results projection and restrictions creation.

Diffuse reflectance spectroscopic mapping imaging applied to art objects materials determination from 200 up to 5000 nm

The microsampling destructions caused by the sampling of analytical spectroscopic methods are generally not permitted to art objects. Consequently, the development of nondestructive analysis techniques is a necessity. In this work we present a set of signal processing and artificial intelligence techniques which support the operation of a novel device developed for the nondestructive identification of art objects. The proposed device combines ultraviolet, visible, near infrared, and midinfrared spectroscopy in diffuse reflectance mode to identify the materials that exist in each paint layer of an artwork.

Measuring the protective role of clay-based renders in adobe masonry using thermal imaging and ultrasonic velocity imaging

The protective role of renders in masonry is well recognized. Renders constitute a constructing tradition since clay-based masonry but they were extensively used also in stone and brick structures up to modern concrete domination. Nevertheless, the positive role of renders cannot be measured and it is a rather qualitative parameter. In the present paper, unrendered and rendered adobes were used as masonry units. Two different render types were used. In one case, clay and lime were combined as binders while in the second one, cement was used. The techniques used to measure the final pathology were ultrasonic velocity imaging and thermal imaging. The aim is to suggest a methodology which can measure the deterioration and give a quantitative rather than qualitative evaluation.