1. In an imaging device having a scanned document input and a controller for executing instructions responsive thereto, a method for coarsely classifying whether or not an unknown input document belongs to a group with one or more reference documents, comprising: receiving at the controller a scanned input from the scanned document input for each of the unknown input document and the one or more reference documents; determining counts of contours of the scanned input for said each of the unknown input document and the one or more reference documents; and determining inclusion or not in the group by comparing said counts of contours between images corresponding to the unknown input document and the one or more reference documents.