Summed-area tables for texture mapping

TLDR

Texture-map computations can be made tractable through precalculated tables independent of texture density, as exemplified by mip maps that use successively lower-resolution tables filtered from the discrete texture function. The study proposes an alternative method that uses a single integral table of the texture function to potentially achieve superior results at comparable cost. The authors detail the algorithms that support the integral-table technique. The cost and performance of the new technique are compared to previous methods.

Abstract

Texture-map computations can be made tractable through use of precalculated tables which allow computational costs independent of the texture density. The first example of this technique, the “mip” map, uses a set of tables containing successively lower-resolution representations filtered down from the discrete texture function. An alternative method using a single table of values representing the integral over the texture function rather than the function itself may yield superior results at similar cost. The necessary algorithms to support the new technique are explained. Finally, the cost and performance of the new technique is compared to previous techniques.