ELECTRONIC GRAPHIC ARTS SCREENER

摘要

A halftoning apparatus utilizes a contone line buffer (913), an image handler (930), a screen handler (950) and a font memory (970). The contone line buffer successively provides each contone value that exists within a line of an image that is to be screened. The image handler tracks the location of a current image bit being produced by the screener. The screen handler determines the correct bit, which corresponds to the image bit location, that is to be sampled within any stored halftone dot pattern in the font memory. The font memory stores a different halftone dot pattern for each different contone value. Each contone value is used to select a particular reference halftone dot pattern that is to be sampled; while the sampling coordinates are used to access a particular bit within that pattern.