Apparatus for representing continuous tone and high contrast images on a bilevel display
US4992955A · kind A · utility
20Cited by
7References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1988 |
| Grant date | Feb 12, 1991 |
| Priority date | — |
| Expiry date | Oct 24, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4055
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A half tone display apparatus using a display apparatus of bilevel representation in white and black is provided. The apparatus includes a unit supplied with a multilevel image such as a color image, a device for detecting edges in characters, patterns and photographic images, a unit for deriving a level difference between pixels adjacent to the edge, and a control unit for forcibly displaying a pixel of the edge portion as a white or black pixel for emphasis provided that the level difference is not larger than a predetermined threshold and for applying dither conversion to other pixels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.