1. A method of comparing a first document and a second document, wherein the text of each of the first and second documents can be divided up into basic units, the method comprising: generating a first sequence of images of basic units from the first document; generating a second sequence of images of basic units from the second document, wherein the basic unit images of the first sequence and the second sequence include characters, words, lines, or paragraphs; comparing the basic unit images of the first sequence with the basic unit images of the second sequence to identify matches between the basic unit images of the first sequence and the second sequence and identify differences between the basic unit images of the first sequence and the second sequence, wherein the comparing includes: calculating a coarse distance measure between the basic unit images of the first sequence and the second sequence to align the basic unit images; and calculating a fine distance measure between aligned basic unit images of the first sequence and the second sequence to identify differences between the aligned basic unit images of the first sequence and the second sequence, wherein the fine distance measure is performed at a higher resolution than the coarse distance measure; and outputting information about the differences between the first document and the second document.
1. A method of comparing a first document and a second document, wherein the text of each of the first and second documents can be divided up into basic units, the method comprising: generating a first sequence of images of basic units from the first document; generating a second sequence of images of basic units from the second document, wherein the basic unit images of the first sequence and the second sequence include characters, words, lines, or paragraphs; comparing the basic unit images of the first sequence with the basic unit images of the second sequence to identify matches between the basic unit images of the first sequence and the second sequence and identify differences between the basic unit images of the first sequence and the second sequence, wherein the comparing includes: calculating a coarse distance measure between the basic unit images of the first sequence and the second sequence to align the basic unit images; and calculating a fine distance measure between aligned basic unit images of the first sequence and the second sequence to identify differences between the aligned basic unit images of the first sequence and the second sequence, wherein the fine distance measure is performed at a higher resolution than the coarse distance measure; and outputting information about the differences between the first document and the second document. 4. A method according to claim 1 wherein the step of generating a second sequence of images from the second document comprises: deskewing an image of the second document by identifying horizontal lines of text in the image of the second document; and dividing up the image of the second document into lines in the direction of the identified horizontal lines and then dividing up the lines into words in the horizontal direction to obtain the word images.