Machine vision method and apparatus for finding an object orientation angle of a rectilinear object
US6002793A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 1994 |
| Grant date | Dec 14, 1999 |
| Priority date | — |
| Expiry date | Oct 26, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V10/242
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A machine vision system for finding an angle object orientation, or other characteristic, of an object in an image. The system determines the boundary pixels, determines the segment orientation angles associated with each successive segment of n boundary pixels, assigns a weight to each angle, generates a histogram of the angles according to their weights, normalizes the histogram to an angle range covering 90.degree., and generates a signal representing the angle corresponding to a selected peak in the histogram. In one embodiment, the system interpolates between neighboring pixels across the boundary to obtain a grey-scale boundary of sub-pixel accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.