David Saunders and John Cupitt
Technical Bulletin Volume 14, 1993
Describes the second-generation system used to detect and measure changes in the surface colour of paintings. It comprises a high-resolution monochrome digital camera mounted on a positioning system, which carries a filter set placed in front of the camera. Areas of the painting and of calibration charts are illuminated sequentially through the filters, and combined into a high-resolution colourimetric image of the whole painting.
At times 10–20, or even 40, pixels (picture elements) per mm are required to give adequate resolution, and large paintings are dealt with by taking subimages and combining them electronically. Details of the equipment, calibrations, storage of data, etc. are given. Changes in surface texture after transport can also be measured.
colour, filters, image processing, National Gallery (London), VASARI project
Image Processing at the National Gallery: The VASARI Project, David Saunders and John Cupitt (text-only RTF 0.24MB)
To cite this article we suggest using
Saunders, D., Cupitt, J. 'Image Processing at the National Gallery: The VASARI Project'. National Gallery Technical Bulletin Vol 14, pp 72–85.