Patent ID: 7016908

Claim:
A computer implemented file processing method for compressing a section of data and index data comprising: dividing both the data and the index data into a plurality of sections, wherein the index data is different from the data, the index data corresponds to the data and is used to search or retrieve the data, where each of the sections comprises the data and the index data, and the data comprises at least one of text data, image data, and audio data; creating a conversion table for each section by selecting a predetermined number of 16-bit codes within the data in an order of appearing frequency, decomposing remaining non-selected 16-bit codes into 8-bit codes, and selecting the 8-bit codes in an order of appearing frequency; compressing each of the sections based on the conversion table created therefor using a corresponding one of a plurality of different compression parameters to obtain a compressed file; storing the compressed file in a storage medium together with address information and the different compression parameters of the sections after compression; and expanding at least one of the sections in the compressed file read from the storage medium using the corresponding one of a plurality of different compression parameters for each section.