Image filtering in HSI color space
US6631206B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 2000 |
| Grant date | Oct 7, 2003 |
| Priority date | — |
| Expiry date | Mar 22, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/20192
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for filtering an angular signal which avoids errors in averaging and differencing operations. Components of a hue signal are separated into groups based upon the sign of a corresponding filter coefficient ai for the respective component and the range of the hue component value vi. A weighted mean is computed for each of the groups. The weighted mean of the resulting values having positive filter coefficients and the weighted mean of the resulting values having negative filter coefficients then are derived. The computed value is redefined if needed to be in modulus 2&pgr;. The weighted distance of the two values then is derived. The result is the filtered hue value for a given image data pixel. A filtered hue value is obtained in the same manner for each image pixel of a desired image object or of a given image frame.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.