8. The method of claim 1 , wherein the computing a comparison measure between the query object and each of the quantized database objects is lower-bound-based.
1. A method for comparing a query object and a set of database objects comprising: providing quantized representations of database objects which have each been transformed with a quantized embedding function which is the composition of a real-valued embedding function and a quantization function which embeds the representations in a quantized embedding space composed of quantized values; transforming the query object to a representation comprising a vector of k dimensions in a real-valued embedding space using the real-valued embedding function; computing a set of query-independent expected values comprising computing, for each of the k dimensions, a first average expected value in the real-valued embedding space for a first sample of database objects having a first of the quantized values in the quantized embedding space and a second average expected value in the real-valued embedding space for a second sample of database objects having a second of the quantized values in the quantized embedding space for the dimension; storing a set of computed query-dependent estimated distance values for the query object, based on the distance from the transformed query object to the computed set of query-independent expected values; and computing a comparison measure between the query object and each of the quantized database object representations based on the stored query-dependent estimated distance values; and outputting data based on the comparison computation.