Facial feature detection on mobile devices
US7643659B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 2005 |
| Grant date | Jan 5, 2010 |
| Priority date | — |
| Expiry date | Oct 30, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/19
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Locating an eye includes generating an intensity response map by applying a 3-rectangle filter and applying K-mean clustering to the map to determine the eye. Locating an eye corner includes applying logarithm transform and grayscale stretching to generate a grayscale eye patch, generating a binary map of the patch by using a threshold based on a histogram of the patch, and estimating the eye corner by averaging coordinates weighted by minimal eigenvalues of spatial gradient matrices in a search region based on the binary map. Locating a mouth corner includes generating another intensity response map and generating another binary map using another threshold based on another histogram of the intensity response map. Locating a chin or a cheek includes applying angle constrained gradient analysis to reject locations that cannot be the chin or cheek. Locating a cheek further includes removing falsely detected cheeks by parabola fitting curves through the cheeks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.