1. A method for similarity search, comprising: transforming sequence data into a compressed sequence represented by top-k coefficients of the sequence data and a sum of the energy of omitted coefficients of the sequence data; and computing at least one of a lower bound and an upper bound on a distance range between a query sequence and the compressed sequence, given a first and a second constraint, the first constraint being a sum of squares of the omitted coefficients being less than a sum of the energy of the omitted coefficients, the second constraint being the energy of the omitted coefficients being less than the energy of a lowest energy one of the top-k coefficients.