Image color modification method and apparatus employing unsharp masking
US5682443A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1994 |
| Grant date | Oct 28, 1997 |
| Priority date | — |
| Expiry date | Mar 21, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/58
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for modifying an image defined by data representing the colour component content of each pixel of the image. The method comprises, for each colour component of each pixel, PA1 (a) generating unsharp (U) and sharp (S) data and performing an unsharp masking algorithm on the sharp and unsharp data to generate fringe data (F); PA1 (b) modifying the fringe data with a weighting function (.phi.) determined in accordance with the values of the sharp or unsharp data for all of the colour components of the pixel; and PA1 (c) combining the modified fringe data with the pixel data to generate modified pixel data. By applying a weighting function related to all the unsharp values for the pixel and hence to the input colour component content of the input signals of a particular sample area, the fringe amplitude is varied according to the colour of the region thereby enabling sharpening or smoothing to be appropriate to the part of the image e.g. sharpening hair and smoothing skin colours.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.