Practice-Based Comparison of Imaging Methods for Visualization of Toolmarks on an Egyptian Scarab

Abstract

Abstract. 3D representations were made of a small Egyptian scarab with a gold band by a number of methods, based on photogrammetry and photometric stereo. They were evaluated for colour fidelity and spatial detail, in the context of a study of toolmarks and manufacturing techniques of jewellery in ancient Egypt. It was found that although a 3D laser scanner gave the best geometric accuracy, the camera-based methods of photogrammetry and photometric stereo gave better representation of fine detail and colour on the object surface.Keywords: Digital heritage, image acquisition, 3D imaging, visualisation, gold. Introduction and research scopeLittle is known about Egyptian jewellery dated to the Bronze Age and the practices of the goldsmith. With the exception of studies by Schorsch [1] and Lucas [2], the main analytical researches carried out until recently concerned the collections of the Metropolitan Museum of New York: jewellery from the burial of Wah [3], jewellery from the burial of the foreign wives of Thutmose III [4], and a large set of aurian silver objects from the Ashmolean Museum of Oxford [5]. As a result, neither the goldsmithing practices in Ancient Egypt -alloys and manufacturing technologies -nor the origin of the gold was understood. In 2009 however, two multi-disciplinary studies of the Ancient Egypt collections of the National Museums Scotland [6,7] shed more light on this jewellery and raised new questions on a very particular period of Egyptian history, the 2nd Intermediate Period (1650( -1550. This led to multi-disciplinary studies of other collections, including the British Museum [8], which applied elemental analysis to determine the composition of alloys, the origin of the gold and the evolution of practices for joining and decorating the objects.The CNRS PICS project 5995 entitled Study of Bronze Age Egyptian Gold Jewellery has involved exchanges between several French and UK institutions. The focus is on the origin of gold and composition of the alloys used for forming, soldering, and decorating, in order to provide new evidence on the technologies used in the Egyptian Accepted manuscript of paper. MacDonald, Lindsay, Guerra, Maria Filomena, Pillay, Ruven, Hess, M., Quirke, Stephen, Robson, Stuart, & Hosseininaveh Ahmadabadian, Ali. (2014). Practice-based comparison of imaging methods for visualization of toolmarks on an Egyptian Scarab.

Modelling the appearance of heritage metallic surfaces

“…The specular colour for glossy surfaces on the majority of materials is the colour of the illumination, but for metals it is the colour of the metal. The effect is particularly striking for gold (see MacDonald et al, 2014).…”

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“…(2014) made a detailed analysis for an Egyptian scarab from the Second Intermediate Period and the New Kingdom. Their analysis demonstrated the existence of very thin and very thick hard-soldering, using the casting process even for very small items, the re-use without re melting of some smaller elements with copper and silver content [12]. Hassaan (2017) Sparavigna (2009) in her study of Egyptian seals and scarabs presented some inscribed scarabs in display in the Egyptian Museum of Torino.…”

“…He presented in the inscription in a separate image including two Cartouches of the Pharaoh in the last line, then an English translation made a detailed rom the Second Intermediate Period and the New Kingdom. Their analysis demonstrated the existence of very thin and soldering, using the casting process use without remelting of some smaller elements with different copper and silver content [12]. Hassaan (2017) in his study of scarab statuettes in ancient Egypt presented inscribed scarabs from the 13 th Dynasty, Dynasties, Second Intermediate Period, th Dynasties, Dynasty [3].…”

Development of a platform recommending 3D and spectral digitisation strategies

“…MacDonald, Guerra, Pillay, Hess, Quirke, Robson, & Ahmadabadian, 2014;Wefers & Cramer, 2015;Wefers, Reich, Tietz, & Boochs, 2016), buildings (e.g. De Luca, 2013Kersten, Hinrichsen, Lindstaedt, Weber, Schreyer, & Tschirschwitz, 2015), paintings (e.g.…”