1. A computer-implemented method for creating a set of indexes for a collection of documents according to document layout, comprising: providing a plurality of documents to computer memory; extracting layout blocks from the provided documents; using a computer processor, clustering the layout blocks into a plurality of layout block clusters; computing a representative block for each of the layout block clusters; generating a document index for each provided document based on the layout blocks of the document and the computed representative blocks; clustering the created document indexes into a plurality of document index clusters; generating a representative cluster index for each of the document index clusters; and outputting the generated document indexes, representative blocks, document index clusters, and representative cluster indexes to memory.