Method of font rendering employing grayscale processing of grid fitted fonts
US5684510A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1994 |
| Grant date | Nov 4, 1997 |
| Priority date | — |
| Expiry date | Jul 19, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/24
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of displaying characters on a pixel oriented grayscale display device having a predetermined pixel resolution employing parametric, geometric glyph descriptors is disclosed. The process supports a client process that passes a request for a particular font and a physical character height for the displayed characters as well as the physical resolution expressed in pixels for unit length. A character space height value in pixels is determined and compared to selected values to determine whether the character space height in physical pixels falls into one of three distinct ranges. If within the smallest range, no hinting or grid fitting is performed and the physical pixel coordinates of a scaled glyph descriptor are scan converted using subpixel coordinates. The on subpixels within each pixel are counted to provide a grayscale value for illuminating that particular pixel. If the character space height is in the highest range, the same process is performed after the scaled glyph descriptor is hinted to physical pixel boundaries. Character space heights in the mid range are hinted to the physical pixel boundary but scan converted using a conventional scan converter for the physi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.