1. A system for performing image-based diagnosis of a machine, comprising: a database containing a plurality of historical images taken from a plurality of machines, the plurality of historical images comprising a plurality of ideal images generated from the plurality of machines using all possible machine settings and a plurality of artifact images generated from the plurality of machines, each of the artifact images having known faults associated therewith and a corresponding corrective action for repairing the faults; and a diagnostic unit for diagnosing a new artifact image from a machine having an unknown fault, the diagnostic unit comprising a diagnostic image processor comprising means for finding an ideal image from the plurality of historical images that most closely matches the new artifact image, means for assigning an artifact category to the new artifact image based on the matched ideal image, and means for extracting an artifact feature from the new artifact image according to the assigned category; and a diagnostic fault isolator comprising means for generating a plurality of metrics for the extracted artifact feature and means for applying the plurality of metrics to identify an artifact image from the plurality of historical images that most closely matches the new artifact image and a corrective action for repairing the unknown fault.