Tutorial: Ten-Bit Processing in an 8-Bit Environment

Processing of 8-bit video signals conforming to CCIR Rec. 601 can result in visible artifacts, particularly in gradually shaded areas of an image. Much confusion has resulted from different manufacturers' approaches to this problem and, in fact, no one approach yields a complete solution. This article examines the reason for the artifacts, the adequacy of the Rec. 601 standard, the need for a wider processing path, the advantages and penalties of a wider interconnect path, and the applicability of different techniques to various parts of the system. It concludes that, with careful systematization, excellent quality can be achieved without violation of any of the existing standards.