A completely automated method for classifying electronic images of commercial documents such as invoices, bills of lading, explanations of benefits, etc. is based on the layout of the documents. A document is classified as belonging to a class of similarly laid out images if its distance, determined by a set of pre-defined metrics, to any of the template layouts from the same class of template layouts does not exceed a certain user-defined threshold. Alternatively, if the sum of distances from a given image to several template layouts from the same class does not exceed a user-selected threshold, the image is deemed to belong to a class of images with a specific layout.