Extraction of Stroke Feature Based on Gray Value Distribution

Analysis of Gray Value Distribution in Line and Applicationto Judgement of Classic Works by Writing-Brush

Abstract

“Rinbo” and “Toumo” are techniques of calligraphy. “Rinbo” is a technique of penmanship in which a copy is made by putting the original on the side of a writer. “Toumo” is a kind of techniques for reproduction which is supposed as a tracing technique in which a copy is produced by putting the original under a paper. Connoisseurs have distinguished autographs from copies depending on their experience, knowledge and subjective sence. We deal with three ancient works written by writing brush in China, “Shinsousenjimon”, “Souranjo” and “Chinbimei shinshiken shikoudaiji” as the subjects of this study. It has been supposed that “Shinsousenjimon” was written by “Toumo” However, Prof. Uozumi who is an experienced calligraphist hypothesizes that “Shinsousenjimon” is an autograph or a work by “Rinbo”. It is no doubt from past literatures that “Souranjo” was written by “Toumo” and that “Chinbimei shinshiken shikoudaiji” is an autograph. We examine the density distribution of characters in these images. First, we perform multistage binalization of characters in order to compare overall density distribution in respective characters. Next, we measure the distances between most dark lines and geometrical central lines in several straight parts of characters. Lastly, we compare the density between symmetrical points in several lines of characters. As the result of these analyses, we found that “Shinsousenjimon” has characteristics in more common with those of “Chinbimei shinshiken shikoudaiji” than those of “Souranjo”.