A method of quickly and automatically comparing a new document to a large number of previously seen documents and identifying the document type. First, provide a plurality of document type distributions, each document type distribution describes layout characteristics of an independent document type and may include a plurality of data points. Each document type distribution includes data derived from at least one basis document signature which may include data defining pixels of a low-resolution image of the independent basis document resolved to between 1 and 75 dots per inch or may include document segmentation data derived from the independent basis document. Next provide a new electronic document. Then create new document signature from the new electronic document. Next, distances between the new document signature and each of the plurality of document type distributions are calculated using an algorithm based on a Bayesian framework for a Gaussian distribution. The distances calculated may be Euclidean distances or may be Mahalanobis distances. Additionally, calculating the distances may include weighting the value given each of a plurality of data points in the document signatures based on the usefulness of each of the plurality of data points in distinguishing between the document signatures. Next, select at least one candidate document type for the new electronic document from among the independent document types described by the plurality of document type distributions. The selection of the at least one candidate document type may include selecting a preselected fixed number of the independent document types or may include selecting the independent document types described by those of the plurality of document type distributions having calculated distances that are within a preselected threshold distance of the smallest of the distances calculated. In addition, the invention provides for a program storage medium readable by computer, tangibly embodying a program of instructions executable by the computer to perform the method steps described above.