Mike Day: Faster filters using bilinear texture look-ups There’s a fairly standard technique which uses carefully-placed bilinear taps to halve the number of texture look-ups needed to implement a given filter. This document provides a technique which can, under certain conditions, eliminate one additional look-up from each of the two passes of a separable 2D filter. http://www.insomniacgames.com/mike-day-faster-filters-using-bilinear-texture-look-ups/