Method and apparatus for conversion of outline characters to bitmap characters
US5099435A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1989 |
| Grant date | Mar 24, 1992 |
| Priority date | — |
| Expiry date | Mar 31, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T11/203
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An outline representation of a character or symbol is treated as being composed of a set of zones formed in both the horizontal and vertical directions. The zones are completely character-specific. Each zone defines the extent of some feature of the character. The boundaries of the zones are mapped to specific pixel locations in a bitmap em-square of selected resolution and size. Additional interpolation zones are defined which are used to map all the points on the outline representation of the character that are contained within the interpolation zone, but do not coincide with a control edge, from the positions in the high-resolution em-square to a corresponding position in the low-resolution em-square. To maintain relationships between features, constraint functions may be defined which regulate the size of the control zones for a character at predetermined sizes. Control zones and interpolation zones are all derivatively linked to a basic set of horizontal and vertical control edges at the outline description level. Consequently, the number of computations needed is reduced and the speed with which a bitmap can be generated from the outline representation is increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.