Conversion of a digital camera into a non-contact colorimeter for use in stone cultural heritage: The application case to Spanish granites

In this study, a digital CMOS camera was calibrated for use as a non-contact colorimeter for measuring the color of granite artworks. The low chroma values of the granite, which yield similar stimulation of the three color channels of the camera, proved to be the most challenging aspect of the task. The appropriate parameters for converting the device-dependent RGB color space into a device-independent color space were established. For this purpose, the color of a large number of Munsell samples (corresponding to the previously defined color gamut of granite) was measured with a digital camera and with a spectrophotometer (reference instrument). The color data were then compared using the CIELAB color formulae. The best correlations between measurements were obtained when the camera works to 10-bits and the spectrophotometric measures in SCI mode. Finally, the calibrated instrument was used successfully to measure the color of six commercial varieties of Spanish granite.

Catalytic conversion of solvent refined coal to liquid products /

"LBL-6807."

Conversion of cattle feedlot manure to ethylene and ammonia synthesis gas,

"Grant No. S-802934."

Analysis of the application of thermogalvanic cells to the conversion of low grade heat to electricity /

"Work Performed Under Contract No. AC02-77CH00178."

The rate of conversion of cinchonine to cinchotoxine.

Type-written ms. of thesis. May, 1915.

Conversion of decision tables into decision trees.

Originally presented as the author's thesis, University of Illinois at Urbana-Champaign.