15. A storage medium storing instructions executable by a computer to perform a method as set forth in claim 1 .
1. A method comprising: partitioning a region of interest into a plurality of soft bin regions that span the region of interest; estimating an integral over each soft bin region of a function defined over the region of interest; and outputting a value equal to or derived from the sum of the estimated integrals over the soft bin regions spanning the region of interest.