Method and apparatus for tile based depth buffer compression

摘要

A method and apparatus are provided for compressing depth buffer data in a three dimensional computer graphics system. The depth buffer data is divided into a plurality of rectangular tiles corresponding to rectangular areas in an associated image. The number of starting point locations in a tile are identified and a difference in depth value determined between each starting point and depth values of each of at least two further locations. Using this information depth values are predicted at a plurality of other locations in the tile and where these predicated values substantially match an actual depth value at location is assigned to a plane associated with respective starting point. Starting point location depth value difference data and plane assignment data for each tile and locations in the tile not assigned to a plane, then stored.