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Anti-Aliasing Video Lookup Table

IP.com Disclosure Number: IPCOM000063644D
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18

Publishing Venue

IBM

Related People

Authors:
Bantz, DF Gupta, S Sholtz, PN [+details]

Abstract

Raster scan displays which are only capable of turning the electron beam "on" or "off" exhibit a problem commonly called "staircasing" or "jaggies" (Fig. 1). This problem can be removed using a technique known as anti-aliasing which avoids the problem of the sudden jumps by changing the intensity gradually, and hence using the intermediate intensity levels to remove the "jaggies". Fig. 2 shows blown-up images of how characters and lines can be anti-aliased. This technique relies on the CRT having the capability to display multiple intensity levels. To use anti-aliasing, the display controller has to store additional intensity information. For a character display, this information is stored as part of the character definitions.