1. A method for detecting similar objects in a collection of such objects, the method comprising: processing, by a computer processor, a query to produce the collection of objects; constructing a plurality of has tables collecting objects produced by processing the query; and, for each of two objects: modifying a previous method for detecting similar objects so that memory requirements are reduced while avoiding false detections approximately as well as in the previous method, wherein the modifying comprises: combining. by the computer processor, four samples of features into seven supersamples; compressing each of the seven supersamples into sixteen bits of precision; constructing fifteen hash tables storing combinations of the supersamples; comparing the supersamples using the fifteen hash tables; and requiring a number of matching supersamples out of the seven supersamples in order to concluded that the two objects are sufficiently similar, wherein the number of matching supersamples is greater than a number of matching supersamples required in the previous method.