1. A method of identifying an object by use of a system that includes a database of feature models of known objects having known optical code information associated therewith, the feature models including visual features that are geometric point features corresponding to points on the known objects, the method comprising: attempting to read an optical code on an object, the optical code encoding a set of characters; decoding a portion of the optical code to obtain an item-filter parameter comprising incomplete information encoded in the optical code, the incomplete information corresponding to a decoded subset of the set of characters encoded in the optical code, the decoded subset including at least one member and fewer than all members of the set of characters; when the item-filter parameter is obtained, generating a filtered subset of feature models from the database of feature models based on the item-filter parameter, each feature model of the filtered subset of feature models corresponding to a known object whose associated known optical code information includes the decoded subset; capturing an image that includes a representation of the object, wherein the object is a physical item; extracting visual features from the image, the extracted visual features being geometric point features corresponding to points on the object; and comparing the extracted visual features to those of the feature models of the filtered subset of feature models to identify a match between the object and a known object.