Abstract
Quality of building stone is mainly evaluated by the color and tone for a dressing material in Japanese architecture. The color of stone is measured and evaluated by visual observation and/or a trichromatic colorimeter. However, the former has the demerit such as lacking of reproducibility of evaluation because evaluated result depends on an observer's experience and sensitivity. The demerit of the latter is that it confounds colors of two or more of composed minerals. To solve these problems, this study proposed new color measuring method by using a digital camera with high accuracy. Moreover, new quantitative indexes concerning color and tone were proposed from the results obtained with the proposed method. It was clarified that these indexes are effective for color evaluation of stone.
