Measurement and control of colour fidelity in scanned 3D models for heritage conservation

Abstract

• 3D models of archaeological objects do not usually provide metadata colour fidelity. • Improving the colour information from 3D scanners is an open issue. • Colour calibration used in photography is applied to the modelling process. • The profiling operation improves the colour fidelity of 3D model images. Colour calibration is a common procedure in the photography of archaeological objects, and there are sufficient tools to guarantee faithful digital (images) or analogue reproductions (paper printing, screen or display projectors, etc.). The 3D models obtained both photogrammetrically and, above all, by means of 3D scanners have not yet reached this development and are often constructed without much attention to the colourimetric quality of the result. Because of these factors, the present work has two objectives: 1) to measure the colour fidelity of 3D models to diagnose potential quality problems and 2) to propose a data collection and processing methodology that allows a significant improvement in the colour fidelity of 3D models built by means of 3D scanners. The methodology of colour calibration used in photography is applied to the modelling process. The construction and application of an ICC (International Colour Consortium) profile on the textures significantly reduce the overall error.