1. A system for determining whether a particular product has a predetermined appearance comprising: a filter; first means for defining a low variance region in said filter from a first region of each of a plurality of training products having said predetermined appearance, each first region of the plurality of training products comprising subdivisions, each one of the subdivisions of each first region of the plurality of training products being substantially free of variation from a set of corresponding subdivisions of each of the remaining training products in a predetermined image characteristic; means for identifying a first region comprising subdivisions of the particular product corresponding to the first region of the plurality of training products; means for defining a composite value of the first region of the particular product, the composite value defined as a composite of numerical values associated with the subdivisions of the first region of the particular product and indicative of a predetermined image characteristic; means for detecting an amount of variation by which (a) said composite value of said particular product deviates from (b) a predetermined composite value and for identifying said particular product as not having said predetermined appearance if said amount of variation exceeds a predetermined value; second means for defining a high variance region in said filter from a second region having said predetermined appearance, each second region of the plurality of training products comprising subdivisions not identified in the first reason of the plurality of training products, substantially every one of the subdivisions of each second region of the plurality of training products being subject to high variation from the set of corresponding subdivisions of each of the remaining training products in said predetermined image characteristic; means for defining discriminant values associated with the second reason of the training products, the discriminant values defined as a combination of numerical values associated with the subdivisions of the second region of the training products and indicative of a predetermined image characteristic; means for computing a dot product between the defined discriminant values and numerical values associated with the subdivisions of the second region of the particular product and indicative of a predetermined image characteristic; and means for detecting a measure by which said dot product deviates from a predetermined dot product value range and for identifying said particular product as having said predetermined appearance if said measure is within a predetermined range.