The 18th Meeting on Image Recognition and Understanding Measurement and Reproduction of Reflective/Transmissive Lights in Ink Brush Painting on Absorbent Paper

From the viewpoint of archaeology, it is necessary to preserve historical artifacts for posterity. Digital archiving is one of the most effective ways to sustain these ancient objects into the future. In this paper, we focus on archiving handwritten documents with ink brush painting on an absorbent paper. Appearances of the documents can be vary among observing environments as shown in Fig.1. Such difference tells us something about the brushstroke of handwriting, for example. According to a related work [3], it is required to obtain both reflectance and transmittance for relatively thin objects to reproduce the appearance realistically. As for existing digital archives of handwritten documents, there are “Toji hyakugomonzyo” which is a national treasure in Kyoto Prefectural Library and Archives [1] and Lotus Sutra which is an “important cultural property” of Japan in Nara National Museum [2]. Although digital images of them are available on the Web, we cannot make realistic replica of them even if we print the image on a paper. For making realistic replica, it is necessary to consider an optical properties of an ink absorption into the paper. Therefore, we propose a method of measurement that obtains not only reflectance [4] but also transmittance, and duplicates a replica being the same texture representation of the documents by using a consumer printer.