An optimisation study of colour measurements on digitised slides of painted works of art

• Published in: Coloration technology 2000-01, Vol.116 (1), p.23-31
• Main Authors: Sotiropoulou, Sophia, Chryssoulakis, Yannis
• Format: Article
• Language: English
• ISSN: 1472-3581; 0037-9859; 1478-4408
• DOI: 10.1111/j.1478-4408.2000.tb00005.x

This paper deals with the problem of the colorimetric fidelity of digitised colour slides of painted works of art. A six‐matrix conversion model was derived that permitted the transformation of any RGB device‐dependent measurement on digitised colour slides to XYZ CIE 1931 device‐independent values. The model was calibrated against a reference colour chart. Eighty‐one uniformly‐painted colour samples were photographed together with a painting on a 4 × 5 inch colour slide that was digitised using a high resolution scanner. A 3 × 3 transformation matrix, of the corrected R, G and B values and the respective X, Y and Z tristimulus values provided by spectrophotometry, was calculated. The calculated matrix was then applied to a 13th century Byzantine fresco, captured on the same digitised slide, to transform the RGB measurements to XYZ CIE 1931 device‐independent values which were then converted into the L* a* b* CIE 1976 colorimetric system.