Research on an on-line Japanese character input system for visually disabled persons

我们为视障人士，特别是后天失明人士，开发了一套手写的日文文字输入系统。该系统由字符输入板、语音合成器和字符识别系统组成。本系统的主要目的是应用于盲人电子邮件系统。本资助项目取得的成果如下：(1)建立了3216类日文手写体汉字数据库，共收集视障人士和蒙眼人士的手写体汉字约10万个。(2)在线字符识别算法的增强在我们开始这个项目之前，我们已经开发了一个大约1000个类别的日文字符（京词汉字类）的识别算法。我们对该算法进行了改进，应用了3216类日文字符，包括JIS一级汉字、平假名、片假名、符号、字母。(3)根据词级知识选择字符纠错算法。对三种纠错算法进行了比较应用和评价。因此，对于我们的目的，发现Trigram方法是最好的选择。(4)人机界面设备样机研制了一个人机界面设备样机。该装置由右手书写字符的电子板和左手控制系统状态的手控制器组成。(5)视障人士文件控制系统开发了文件管理、文档编辑、电子邮件收发等CPU文件控制系统。

We have developed a pen-based Japanese character input system for the visually disabled persons, especially persons with acquired blinds. This system is composed of a character input tablet, a voice synthesizer and character recognition system. The main purpose of this system is to be applied to an electronic mail system for the blind persons. The results we got in this grant term are as follows:(1) Data base construction of the handwritten characters 3216 categories of Japanese characters, totally about 100 thousand characters were gathered from visually disabled persons and blindfold persons.(2) Enhancement of on-line character recognition algorithm Before we started this project, we had already developed an recognition algorithm for about 1000 category Japanese characters (Kyoiku Kanji Category). We enhanced this algorithm to apply 3216 category Japanese characters, including JIS No. 1 level Chinese characters, Hiragana, Katakana, Symbol, Alphabet.(3) Selection of the error correction algorithms of characters by word level knowledge. Three kinds of error correction algorithm were comparatively applied and evaluated. As the result, the Trigram method was found to be a best choice for our purpose.(4) Prototype of man-machine interface device We developed a prototype of man-machine interface device. This device is composed of an electric tablet for writing a character by the right hand, a hand controller for controlling the system condition by the left hand.(5) Document control system for visually disabled persons Document control system in CPU, like file management, document editing, and e-mail receiving/transmitting, was developed.