The Next Step in Digital Archiving

         As of now, the VASARI project is the basis for many research projects.  Much work is being done in the area of texture analysis.  It has also been found that connecting  an infrared camera to the system will create images of the underlying drawings.  This  finding is useful for the creation of low-res images for public-access systems and  for teaching tools.

        In the area of color change measurement, the effects of the VASARI have helped. This is still a difficult procedure, since in order to measure the change of, say a  pixel, we must somehow place the previous image of the said pixel on top of the present pixel.  This may be complicated, especially when the texture on which the image is  located can or may become warped.  When this occurs, we can do a rough overall analysis of the change of the painting or image.  The procedure for this involves creating a third image based on the deltaE(cmc) values.  This image can provide information on where the greatest amount of aging or other changes are occuring.  Also, it is hoped that this  "error-mapping" may even help to see which paintings age more quickly and relate that  rate to environment.

        With the original VASARI project, the average color error (based on deltaE (ab) ) in even relatively poor conditions was around 4.  In good conditions, that figure was  approximately 3.  With the MARC project, that figure was also around 3.  Originally,  capture time for an image was in the range of hours, but that figure improved dramatically with the MARC project as well.

        In general archiving studies, it has been found that to get color measurement down to the precision of "just perceptively different" is possible but would require 10-bit  analog-to-digital conversion, and preferreably 12-bit conversion.  The original VASARI project featured 8-bit conversion, simply because that is what was used by the Kontron ProgRes 3000.  Work is being done to incorporate 12-bit conversion into the VASARI  project. 

start    back   next