1. A document analysis system comprising: a processor, the processor functioning as: an input unit that receives a document, the document comprising one of structured document or a semi-structured document, renders the received document, and stores the rendered document as an image in a storage unit; a basic layout analysis unit that groups document description elements of the document included in the image that are juxtaposed in a horizontal or vertical direction in the image, relates the grouped document description elements to layout components of the document that describe a layout of the document description elements of the document, and stores the related grouped document description elements and layout components in the storage unit; and an output unit that outputs the layout based on the stored related grouped document description elements and layout components, the layout identifying the layout components, the layout components referencing the grouped document description elements.
7. The document analysis system according to claim 1 , further comprising: an index document output unit generates and outputs an index document based on the document and information of the layout of the document; and an item document output unit that generates and outputs a document which describes a content of an item of the index document based on the information of the layout.