The present invention relies on the two-dimensional information in documents and encodes two-dimensional structures into a one-dimensional synthetic language such that two-dimensional documents can be searched at text search speed. The system comprises: an indexing module, a retrieval module, an encoder, a quantization module, a retrieval engine and a control module coupled by a bus. A number of electronic documents are first indexed by the indexing module and stored as a synthetic text library. The retrieval module then converts and input image to synthetic text and searches for matches to the synthetic text in the synthetic text library. The matches can be in turn used to retrieve the corresponding electronic documents. It should be noted that a plurality of matches and corresponding electronic documents may be retrieves ranked by order according the similarity of the synthetic text. In one or more embodiments, the present invention includes a method for indexing documents by converting them to synthetic text, and a method for retrieving documents by converting an image to synthetic text and comparing the synthetic text to documents that have been converted to synthetic text for a match.