Patent ID: 7043686

Claim:
A data compression apparatus for encoding data and for compressing the encoded data comprising: a grammar storage unit for storing grammar rules for a tree local language in which data are represented by a labeled tree structure; an encoder for reading a document written in said tree local language, for dividing said document into a structure part and contents, and for encoding said structure part using said grammar rules stored in said grammar storage unit; and a compressor for compressing said contents of said document extracted by said encoder; and wherein said encoder includes; a divider for dividing a target document into a structure part and contents; an automata constructor, for constructing pushdown automata that correspond to said grammar rules; and an encoded data generator, for employing said pushdown automata that are constructed by said automata constructor to perform syntax analyzation of said structure part of said document that is obtained by said divider, and for generating an encoded data string for said structure part.