Method for producing contrast-controlled grayscale characters
US5796409A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 1993 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | Apr 6, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2215/0068
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The invention teaches grayscale specific character outline modification techniques for synthesizing contrast controlled grayscale pixmap characters of improved appearance at any resolution and size. In addition, methods for computing the visually optimal spacing of any two characters taking into account outline shape modifications induced by the character contrast control method. The synthesis of contrast controlled grayscale characters may include the following outline modification steps: (1) modifying the height of the character by placing its reference lines on pixel boundaries of the target pixel array, (2) verifying and correcting the width of character strokes such as bars and curved stems, (3) modifying the placement of vertical and horizontal bars and of bar-like terminal elements so as to ensure that each bar or terminal element has at least one high-contrast edge, (4) modifying the placement of vertical and horizontal curved stems so as to ensure similar optical correction behavior and similar intensity profile behavior of curved character parts throughout the characters of the considered character set. Visually optimal spacing of characters is obtained by converting the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.