Adaptive coding level control for video compression systems

摘要

An apparatus and method for adaptively compressing blocks of video image data provide a local coding level (34) for use in compressing successive blocks of video image data. Each block is preliminarily compressed (30) using a global coding level. The preliminarily compressed data is processed (32) to provide a measure of the randomness of an image area represented by the block of video image data. A local coding level is generated (34) based on the randomness measure. The video image data is then compressed (36) using the local coding level to provide compressed data for transmission. One or more intermediate compression stages (16, 18) can be provided, each generating an intermediate coding level (ICL), to better refine the randomness measure for use in generating the local coding level. <IMAGE>