Document layout analysis
Document layout is formally defined in the international standard ISO 8613-1:1989 (Open Document Architecture (ODA) and interchange format ).
Layout analysis software
OCRopus – A free document layout analysis and OCR system, implemented in C++ and Python and for FreeBSD, Linux, and Mac OS X. Developed by a German Institute (German Research Centre for Artificial Intelligence in Kaiserslautern) and sponsored by Google.
OCRFeeder – An OCR suite for Linux, written in python, which also supports document layout analysis. This software is actively being developed, and is free and open-source.