The method compares a first document 10 and a second document 20. The documents may be scanned in 110,112 or an electronic image formed in other ways 114,116. Each electronic image is then segmented into basic units 14,24 such as words, lines or paragraphs. Differences between the matched basic units 14, 24 are determined and a document 30 representing the differences is created 130 and output 132.