Software-based procedure for conversion of a scalable font character bitmap to a gray level bitmap
US5657430A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1996 |
| Grant date | Aug 12, 1997 |
| Priority date | — |
| Expiry date | Mar 7, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2215/004
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A binary pixel bitmap image is converted to a multi-bit gray level pixel image at a level of resolution that is reproducible by a laser printer. An edge smoothing procedure is employed by the laser printer and comprises the steps of: deriving from font contours of the image, a binary pixel bitmap of the image at a higher level of resolution than is output by the laser printer; logically stepping an m.times.n pixel window across pixel groups of the higher resolution binary pixel bitmap and, at each step, determining a count of pixels of one binary kind that are present within the pixel window; converting each count of pixels to a corresponding modulation signal; and controlling a laser in the laser printer in accordance with each modulation signal so that an edge smoothed gray level image is produced at the printer's level of output resolution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.