CJKV Information Processing, 2nd Edition

Input Methods

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In an attempt to allow for a mixture of one- and two-byte characters, several CJKV encod-

ing methods have been developed. As you will learn in Chapter 4, these encoding meth-

ods are largely, but not completely, compatible. You will also see that there are encoding

methods that use three or even four bytes to represent a single character!

e most common Japanese encoding methods are ISO-2022-JP, Shi-JIS, and EUC-JP.

ISO-2022-JP, the most basic, uses seven-bit bytes (or, seven bits of a byte) to represent

characters, and requires special characters or sequences of characters (called shiing char-

acters or escape sequences) to shi between one- and two-byte modes. Shi-JIS and EUC-

JP encodings make generous use of eight-bit characters, and use the value of the rst byte

as the way to distinguish one- and multiple-byte characters. Now, Unicode has become

the most common encoding for Japanese.

Input Methods

ose who type English text have the luxury of using keyboards that can hold all the keys

to represent a sucient number of characters. CJKV characters number in the thousands,

though, so how does one type CJKV text? Large keyboards that hold thousands of indi-

vidual keys exist, but they require special training and are dicult to use. is has led to

soware solutions: input methods and the conversion dictionaries that they employ.

Most Chinese and Japanese text i ...