Kumamoto University and the major printing company Toppan have succeeded in deciphering documents written in the highly difficult style of cursive script using optical character recognition that combines AI technology. In addition, they have built a keyword search system linked to the system for decoding cursive script documents, making it possible to instantly collect the necessary documents.
According to Kumamoto University, the documents that they have successfully deciphered include a total of about 5 documents from the Hosokawa family, who ruled Higo Province (present-day Kumamoto Prefecture) during the Edo period, including "Hosho," which recorded the orders of the feudal lord Hosokawa Tadatoki, "Gokoku Gosho Anbun," which were copies of letters sent by the feudal lord to his home province during his time at sankin, and "Tokoro e no Johko," which were copies of letters issued by the general magistrates.
The valuable historical documents were entrusted to us by the Eisei Bunko in Bunkyo Ward, Tokyo, which displays documents and weapons related to the Hosokawa family, but they were written in difficult cursive script, which made it impossible to decipher them until now. Therefore, Kumamoto University and TOPPAN used optical character recognition combined with AI technology to decipher the cursive script.
It is said that billions of ancient documents remain throughout Japan, containing detailed records of disasters, epidemics, and local cultures that are directly linked to modern social issues. However, because they are written in cursive script that is difficult for modern people to read, it is difficult to use the records from that time for disaster prevention or the creation of tourism resources.
TOPPAN has been collaborating with the National Institute of Japanese Literature since 2015 to develop optical character recognition technology that can read cursive script. It is expected that the use of a keyword search system equipped with this new technology will make it easier to gather necessary information from ancient documents and accelerate research.
