Browse Prior Art Database

Antialiased Graphics Display WITH Limited NUMBER of INTENSITY LEVELS

IP.com Disclosure Number: IPCOM000063113D
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09

Publishing Venue

IBM

Related People

Authors:
Chase, BD [+details]

Abstract

In a graphics display with a limited set of grey levels the gamma is optimized for color discrimination yet also provides good antialiasing and grey level facsimile. Eight levels of grey are used, increasing in intensity to a power law. A sub-set of grey levels is selected so that when taken in pairs (on either side of a line to be displayed), the combined intensity is the same for each and the relative intensities appear to be at an intermediate position close to the line. The gamma of a display is defined as the exponent in the power law whereby an electrical input signal is transformed to a light output: light output = constant x (volts in)(gamma) Typically, a CRT may have a gamma of 2.5, so in combination with a linear video amplifier the gamma characteristic of a monitor can be close to 2.5.