1. A merchandise checkout system operably coupled to a point of sale (POS) system and a barcode scanner for reading a universal product code (UPC) of an object, the merchandise check out system comprising: one or more imagers for acquiring an image of the object; a data store configured to retain records for a plurality of items, each record comprising a visual model of one of the plurality of items and the UPC of the item; the visual model comprising: a) at least one image of the item; and b) one or more geometric point features extracted from the one or more images of the item; a processor configured to: a) compare the image of the object to the visual model of at least one of the plurality of items; b) recognize the object from the plurality of items based on the image of the object; and c) automatically add the acquired image to the data store if the image of the object does not match the visual model of any of the plurality of items.