Edge enhancement of gray level images
US7079287B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 2000 |
| Grant date | Jul 18, 2006 |
| Priority date | — |
| Expiry date | Nov 12, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4092
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for processing gray level image data. Gray level image data is subjected to plural separate halftone screen processing to form plural separate halftone processed screen gray level image data. The current pixel is also analyzed for contrast index. In response to analysis of the contrast index blending coefficients for processing of the halftone screen modified image data is made. The respective halftone outputs of the screen processings are multiplied by the respective blending coefficient. The resulting blended halftone gray value of the current pixel as well as neighboring pixels are then subjected to a threshold criterion test to determine if this represents a substantially binary image file such as might occur in a saturated text image file. The blended halftone gray value data for the current pixel is subjected to gray level edge enhancement processing to replace certain binary pixels adjacent an edge to reduce anti-aliasing effects. A signal resulting from the threshold criterion test is used to determine whether there is output to the printer or display of an edge enhanced version of the current blended halftone pixel or a pixel value representing the b…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.