Modelling the Rongorongo tablets: A new transcription of the Échancrée tablet and the foundation for decipherment attempts

Abstract

The Rongorongo is a system of writing, still undeciphered, from Easter Island in the Pacific. It consists of a corpus of twenty-six inscriptions, scattered around the world. This article presents the state-of-the art in the study of one of these inscriptions, Text D or the ‘Échancrée’ tablet housed in a museum in Rome, Italy. Through an integrated methodology based on photogrammetry and high-precision structured light scanning, a 3D model of the inscriptions is made available through a public 3D Viewer for the first time. The technique made use of the benefits of both methods of image acquisition: a very accurate, precise, high resolution, and metric reconstruction of the tablet geometry gained through the scanning process, and a high-quality texture achieved through photogrammetry. In addition, we present a new analysis of the text, through a close palaeographic examination of its signs, and corrections of previous hand drawings and transcriptions. The ultimate aim is to reach unbiased ‘readings’ of the signs through an integrated synergy of traditional palaeographic analysis and an advanced 3D model. These, applied to all the inscriptions, constitute the necessary stepping-stones for any decipherment attempt.

A high-resolution photogrammetric workflow based on focus stacking for the 3D modeling of small Aegean inscriptions

“…In the wider context of the 3D documentation of archaeological artifacts, the most widespread solutions are 3D scanning and ultra-close-range digital photogrammetry [57,43]. 3D scanning systems, such as laser scanners and the majority of non-laser-based scanners, are active sensors.…”

“…We used the V-GER ScanRider 1.2 structured-light scanner [61] to collect the reference 3D models of the three nodules, due to its high performances -of the order of few tens of microns (Table 9) -in terms of nominal precision, accuracy and resolution, necessary to reconstruct the smallest details of the inscribed objects under investigation [2,42,41,43]. After an initial stage of calibration, the scanning process was performed using the most accurate scan- ning volume (Table 9).…”