1. An apparatus comprising: a diagnostic image analyzer comprising an image classifier coupled to a controller; the diagnostic image analyzer being operative to receive at least a portion of an image from an image data source and to perform a classification operation on the image in the image classifier based at least in part on information from a knowledge base of one or more previously classified images; wherein the image classifier is configured by the controller to implement an image processing engine for performing at least a portion of the classification operation, the image processing engine comprising an interconnection of at least one image planner element, a plurality of image scrutinizer elements and at least one image aggregator element, said elements being selected for use in the image processing engine from a pool of such elements available to the image classifier; wherein the image subject to the classification operation is subdivided into a plurality of different sub-portions with each such sub-portion having separately-identifiable meta-information associated therewith, a given one of the sub-portions and its associated meta-information collectively comprising an image-meta pair; wherein the image planner element distributes image-meta pairs, corresponding to respective sub-portions of the image subject to the classification operation, to the image scrutinizer elements, each of the image scrutinizer elements compares at least one received image-meta pair supplied by the image planner element against at least one set of one or more image-meta pairs it manages, and the image aggregator element combines results of the image scrutinizer comparisons; and wherein the plurality of image scrutinizer elements are arranged in rows and columns, with each row corresponding to a different one of multiple processing layers, and each column corresponding to a different specified comparison criteria, and wherein image-meta pairs processed by the image scrutinizer elements propagate from a higher one of the processing layers to a lower one of the layers only after matching the specified comparison criteria at the higher layer.