Decompression of block compressed images

Abstract

A system, method, and computer program product that may use a cache in the decompression of block compressed image data. Each data entry in the cache may represent decompressed image data corresponding to a compressed block of an image. The indices of the cache are keys, where each key is the output of a hash process that is performed on the corresponding compressed block. Decompression of a compressed block may be performed by hashing the compressed block to generate the key. The key may be used to access the cache. The decompressed data indexed by the key may be read and used as the decompressed version of the compressed block. If no data corresponds to the key, or if the cached data indexed by this key is otherwise invalid, then a conventional decompression process may be applied to the compressed block to yield the decompressed data. This decompressed data may then be written to the cache, at a location corresponding to the key.

What is claimed is: 
     
         1 . A method, comprising:
 receiving a compressed block of image data, wherein the block represents at least a portion of an image;   hashing the compressed block thereby deriving a key;   using the key as an index to access cached data in a cache; and   performing a validity check of the cached data that determines if endpoint colors in the compressed block match corresponding fields in the cached data that is indexed by the key.