<title>Luminance contouring at the display in digital television</title>

Abstract

Digital processing of video signals can introduce many types of artifacts visible at the final display. One artifact, called luminance contouring, occurs when the number of bits that is output from the final digital processing stage is small enough for the luminance step corresponding to one bit to be visible at the display. While luminance contouring is rarely a problem in CRT displays, it is known to occur in digital micromirror device (DMD), plasma and liquid crystal device (LCD) displays. This paper provides a method to determine if luminance contouring is likely to occur in a given display when driven by a given bit count. Also indicated are the luminance and drive levels where luminance contouring is most likely to occur in common display types, including the DMD, twisted-nematic LCD and CRT displays.