Polygonal approximation method and apparatus for use in a contour encoding system
US5978512A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 29, 1998 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Jul 29, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T9/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus polygonally approximates a contour of an object expressed in a digital video signal. First of all, the apparatus determines a pair of vertices on the contour. Then, a line segment connecting the pair of vertices is generated and widened to thereby produce a band segment. And, a contour segment corresponding to the line segment is detected and, subsequently, the band segment and the contour segment are matched. The band segment is widened to determine a new vertex located between the pair of vertices on the contour until the contour segment is completely covered by the widened band segment. During the band segment widening process, at least one contour pixel on the contour segment, wherein the detected contour pixels, if there are more than one, are last pixels being covered by the widened band segment, are determined and, among the detected contour pixels, a contour pixel, which is closest to a center of a straight line joining the pair of vertices, is determined as the new vertex. Based on the determined vertices, the apparatus recursively performs the above vertex detection process until all vertices on the contour are determined so that the contour is approximated b…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.