1. A method for analyzing a document structure in a presentation file containing objects, the method comprising the steps of: receiving the presentation file; extracting overlap information between the objects in the presentation file and grouping the objects as a parent-child relationship to obtain a first structured data reflecting the parent-child relationship; grouping the objects as a sibling relationship by using a distance information between the objects to obtain a second structured data reflecting the sibling relationship; and outputting at least one of the first structured data or the second structured data as meta-information for the presentation file.