International Journal of Industrial Ergonomics 26 (2000) 549–559 Constraints on handwriting Korean characters to improve the machine readability Baek-Young Choi, Sung-Yang Bang* Department of Computer Science and Engineering, Pohang University of Science and Technology, Pohang 790-784, South Korea Received 28 September 1998; received in revised form 10 December 1999; accepted 1 May 2000 Abstract Realizing the fact that the availability of a practical recognition system for Korean characters handwritten without any constraints is a long way to go, we try to find a set of writing constraints which improve the machine readability significantly. Based on our observation that the majority of the misrecognitions reported are caused by ambiguous characters, we developed a set of writing constraints which maximally disambiguate those characters. Through experiments, we confirmed that the recognition rate of those data handwritten by applying the proposed set of constraints could improve significantly. Also we found through experiments that the writing speed under those constraints could be increased and the number of writing errors could be reduced to a great extent after a small amount of training. Relevance to industry The development of a recognition system for handwritten characters is very hard and hence not possible in the near future. Yet the demand for such a system is increasing since the data input is becoming a major bottle neck for the information age as the processing power and the data transmitting speed continuously increase. Therefore, it is industry’s interest to present a practical alternative rather than a complete solution. # 2000 Elsevier Science Ltd. All rights reserved. Keywords: Writing constraints; Handwriting; Korean characters; Machine readability 1. Introduction Whether it is on-line or off-line, the research goal of handwritten character recognition is to develop a system which can recognize characters freely written by humans. Therefore, we should make our best efforts to develop such a system. However, the development of such a system is not easy and cannot be made possible within a foreseeable future. This reality naturally makes us to rethink about the original goal and to think of some compromise. In other words, we wonder if we can improve the machine readability to the extent of practical use by constraining the way of our writing slightly. And, if such a question makes sense, the next question is how. The research in Korean character recognition has been very active since 1970s. We already have *Corresponding author. Tel.: +82-562-279-2241; fax: +82- 562-279-2299. E-mail address: sybang@postech.ac.kr (S.Y. Bang). 0169-8141/00/$ - see front matter # 2000 Elsevier Science Ltd. All rights reserved. PII:S0169-8141(00)00028-7