Investigation of methods for decision of original coloring from monochrome photographs

基于单色照片的白色对比度取决于（i）感光材料的特性（ii）光源的照明光谱的假设，发现在与参考照片相同的条件下拍摄着色样品的单色照片并比较两者的对比度可以导致原始着色的判定。使用这种方法，确定了琉球王国昭仪王（1813-1847）的肖像的原始着色，据报道，该肖像在第二次世界大战期间丢失。

Based on an assumption that the black and white contrasts of monochrome photographs are dependent on (i) the characteristic of photosensitive materials, (ii) illumination spectra of light source, it was found that taking monochrome photographs of coloring samples under the same conditions as the reference photographs and comparing the contrasts of both can lead to the decision of original coloring. Using this method, decision of the original coloring of a portrait of a king of Ryukyu Kingdom Sho-Iku (1813-1847), which has been reported to have been lost during the World War II, was carried out.