1. An imaging system for localizing a defect on an object under test, the imaging system comprising: an excitation source for applying a test vector to the defect, wherein the defect exhibits a response to the applied test vector; an image detector positioned to receive the response and produce an image therefrom, the image including the defect and a defect-artifact encompassing a location of the defect; and means for classifying the defect-artifact as a specific defect-artifact type, defect-artifact type classifications including a point-type, a line-type, and a corner-type; means for applying an algorithm to the image to locate the defect within the defect-artifact, the algorithm being adapted for the specific defect-artifact type; means for iteratively applying a first morphological filtering algorithm to the image for each of i threshold levels, where i is an integer greater than 1, thereby producing a set of i thresholded images wherein the set of i thresholded images includes the defect-artifact, and means for generating a data structure associating the type-specific defect-artifacts from different type-specific images, the data structure linking a tree of thresholded defect-artifact images using successively greater threshold levels for gradient peak profiling.