1. A computerized image retrieval system having a processor adapted for implementing a quantization tool, the tool comprising: hierarchically quantized data representing a plurality of images organized using a method comprising the steps of: (a) employing the processor for computing a plurality of sets of feature vector information, each set associated with a particular image wherein each said feature vector information within the set represents a detected feature region of interest from said particular image; (b) quantizing each said feature vector information of each of the sets, producing a list of numerical quantities associated with each of the sets; and (c) applying a k-means cluster operation, recursively, splitting each of said lists into a plurality of branched parts, hierarchically organizing the sets of feature vector information into said parts to which said cluster operation is subsequently, likewise, applied.