Patent · US Expired

Combination of transition-encoded font information for generation of superimposed font images

US4857904A · kind A · utility

10Cited by
10References
20Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 15, 1987
Grant dateAug 15, 1989
Priority date
Expiry dateSep 15, 2007

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06K2215/0065
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

Transition-encoded font image information is a form of information flagging all pixel displacement locations upon a scan line of a raster scan image generator, nominally a laser printer, whereat black to white, and white to black, transitions occur during generation of the one scan line of a font image. Transition-encoded information for plural, superimposed, font images may be combined prior to generation of a synthesis image. In this combination of transition-encoded information for generating superimposed font images the flags representing transitions must not be overwritten, there being a limit that a single scan line pixel position must either transit black to white, transit white to black, or maintain the state of the previous pixel. The combining of transition encoded information encodes transitions for these one or ones of addresses (pixels) wherein two flags would otherwise overlap so that the total transitions within the combined font information are preserved. This is accomplished by ripple shifting the position(s) of the transition(s) flag(s) within the second font image information which have identical positional correspondence with transition(s) flag(s) within the fir…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.