1. A method for processing a document, the method comprising: identifying a text area from a scanned document; extracting symbols from the identified text area; acquiring symbol-related information regarding each extracted symbol by a symbol-related information acquirement unit; dividing the extracted symbols, by a symbol division unit, into a plurality of groups based on a preset reference value regarding the symbol-related information; and generating a key index by a key index generation unit by arranging one group of symbols from among the divided groups, wherein the symbol-related information is information regarding at least one of height, width, and stroke width of the corresponding extracted symbol.
1. A method for processing a document, the method comprising: identifying a text area from a scanned document; extracting symbols from the identified text area; acquiring symbol-related information regarding each extracted symbol by a symbol-related information acquirement unit; dividing the extracted symbols, by a symbol division unit, into a plurality of groups based on a preset reference value regarding the symbol-related information; and generating a key index by a key index generation unit by arranging one group of symbols from among the divided groups, wherein the symbol-related information is information regarding at least one of height, width, and stroke width of the corresponding extracted symbol. 5. The method according to claim 1 , wherein the generating of the key index comprises storing the generated key index in an image file format separately from the scanned document, or in a header area of the scanned document in an image file format.