Accurate averaging of elements using integer averaging

摘要

A system and method for efficiently obtaining corrected results when averaging multiple integers together. The invention detects when round off errors occur during integer averaging operations, and determines if the accumulated errors are sufficient to require correction. If so, the result is modified by a correction factor to produce an accurate result. Errors can be detected by examining the even/odd status of pairs of numbers that are being averaged together. The invention can be employed with Single Instruction Multiple Data instructions to process multiple sets of integers in parallel. In one embodiment, the invention is used for averaging pixel values in the compression and/or decompression of digitized moving pictures.