COMPRESSED NAVIGATION MAP DATA

PURPOSE: A method for generating compressed navigation map data based on uncompressed navigation map data is provided to effectively reduce a storage space required for recording the navigation map data. CONSTITUTION: A method for generating compressed navigation map data based on uncompressed navigation map data is as follows. The most frequent substring included inside a building block of the uncompressed navigation map data is determined(21). The determined most frequent substring is recorded in one or more seed blocks of the building block(22). The most frequent substring is substituted for a reference modifier In the building block, a reference modifier with respect to the one or more seed blocks is substituted for the most frequent substring(23) so that compressed blocks of to each building block are generated. The compressed blocks and the one or more seed blocks are recorded for generating the compressed navigation map database(24). [Reference numerals] (20) Start; (21) Determining the most frequent substring; (22) Storing the substring in a seed block; (23) Substituting the substring for a reference modifier; (24) Storing seed and compressed blocks; (26) End;