1. A method of clustering objects, implemented on a computing device, the method comprising: constructing a feature-object database of multiple objects, wherein the constructing comprises, for each of the multiple objects, obtaining the object; extracting features from the object to obtain extracted features; calculating feature values for the extracted features, wherein at least some of the features values are continuous; selecting extracted features to obtain selected features and corresponding selected feature values; quantizing the selected feature values to obtain quantized selected feature values, wherein quantizing comprises identifying the selected feature values as discrete or continuous and transforming the identified continuous feature values into discrete feature values; and building the feature-object database having keys comprising quantized selected feature values; building a connected objects database; building a directed graph of connected objects from the connected objects database, wherein the connected objects database is built from the feature-object database; identifying clusters of connected objects; and evaluating the clusters of identified objects to designate groups of related objects.