1. A method for determining authorship of a handwritten document for which the authorship is not known, the method performed by at least one data processing system, comprising: scanning a document to produce a first scanned image of the document, wherein the first scanned image is a wide-spectrum color image of the document; identifying stylus information corresponding to the document from the first scanned image, the stylus information corresponding to a type of a stylus used to produce the document and indicating physical characteristics of the stylus or an ink used by the stylus to produce the document; identifying authorship information corresponding to the document; determining an authorship of the document based on the stylus information and the authorship information; and storing the stylus information, authorship information, and authorship of the document.