The portrait of King Sargon II: 3D scanning, filtering and computational imaging for semantic data extraction

Abstract

This research work, inscribed into the European Project ITSERR Italian Strengthening of ESFRI RI Resilience, is related to metric analyses from computational imaging and filtering of the 3D high resolution model of the portrait of King Sargon II. The limestone relief fragment (TO 10407, 89 cm in height and 52 in width), which portrays the Neo-Assyrian king (721-705 BC), is one of the masterpieces in the archaeological collection of Musei Reali in Torino. This relief comes from the ancient city of Dur-Šarrukin (Khorsabad) in northern Iraq that was founded by Sargon II and was his royal residence.

The fragment was 3D documented with Artec Space Spider structured-light scanner which has a point accuracy of 0.05 mm of and a 3D resolution 0.1 mm. This produced a detailed mesh that could be used for post-processing analysis to extract semantic data and comprehend details that were hardly apparent: in fact, this fragment is a part of a bigger relief decoration coming from the royal palace but it has been detached and partially brushed for masking damages and cutting imperfections. Computational imaging analyses (Deviation analyses, Multi-Scale Integral Invariant filter, virtual Reflectance Transformation Imaging) allowed non-invasive and precise metric investigations on decoration, unlocking new micrometric details useful for formulating updated hypotheses on decorative apparatus: thanks to these analyses, the lost decorations of the relief have been revealed and are now prominently displayed, then the original decorative apparatus have been reconstructed.