Methods, machines, and machine readable media storing machine-readable instructions for improving classifier performance are described. In one aspect, threshold vectors T.sub.k=(t.sub.1k, t.sub.2k, . . . , t.sub.nk) are input into a classifier that includes a cascade of n classification stages. Each classification stage i has a respective classification boundary that is controlled by a respective threshold t.sub.ik, wherein i=1, . . . , n, n has an integer value greater than 1, k is an integer, and each threshold vector T.sub.k corresponds to a respective operating point of the classifier. Threshold vectors corresponding to respective points on a receiver operating characteristic (ROC) curve approximating a target discrimination performance for multiple operating points of the classifier are identified.