1. An apparatus for extracting a background area of a document image, comprising: means for extracting a set of white rectangles from a processed area of the document image; means for dividing the processed area into a plurality of segments using the set of white rectangles as a separator; means for storing the plurality of segments; and means for reading the plurality of segments in a predetermined order as a processed area, wherein the extracting means, the dividing means, the storing means, and reading means repeat recursively the functions of extracting, dividing, storing, and reading, until the background area of the document image is extracted.