The use of grayscale for improved raster display of vectors and characters

Abstract

Decreasing memory costs will soon allow grayscale displays in low-cost raster graphic terminals. Subtle shadings can be used to provide improvements in line quality and character flexibility which could allow raster displays to compete on better terms with the more expensive calligraphic displays. Algorithms for achieving smooth vectors and rotatable dot matrix characters are outlined and scan conversion is discussed. A discussion of the relation between image quality and number and distribution of gray levels follows, with concluding remarks on costs and other practical matters.