Locality-sensitive binary codes from shift-invariant kernels

Abstract

This paper addresses the problem of designing binary codes for high-dimensional data such that vectors that are similar in the original space map to similar bi-nary strings. We introduce a simple distribution-free encoding scheme based on random projections, such that the expected Hamming distance between the bi-nary codes of two vectors is related to the value of a shift-invariant kernel (e.g., a Gaussian kernel) between the vectors. We present a full theoretical analysis of the convergence properties of the proposed scheme, and report favorable experimental performance as compared to a recent state-of-the-art method, spectral hashing. 1