Unrestricted Character Encoding for Japanese

The glyphs of the Japanese writing system mainly consist of Chinese characters, and there are tens of thousands of such characters. Because of the amount of characters involved, glyph database creation and character representation in general on computer systems has been the focus of numerous researches and various software systems. Character information is usually represented in a computer system by an encoding. Some encodings target specifically Chinese characters: this is the case for instance of Big-5 and Shift-JIS. Tere are also encodings that aim at covering several, possibly all, writing systems: this the case for instance of Unicode. However, whichever the solution adopted, a significant part of Chinese characters remain uncovered by the current encoding methods. Thanks to the properties and relations featured by Chinese characters, they can be classified into a database with respect to various attributes. First, the formal structure of such a database is described in this paper as a character encoding, thus addressing the character representation issue. Importantly, we show that the proposed logical structure overcome the limitations of existing encodings, most notably the glyph number restriction and the lack of coherency in the code. This theoretical proposal will then be followed by the practical realisation of the proposed database and the visualisation of the corresponding code structure. Finally, an additional experiment is conducted to measure the memory size overhead that is induced by the proposed encoding, comparing with the memory size required by an implementation of Unicode. Once the files are compressed, the memory size overhead is significantly reduced.