Circle location
US6178262A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 1994 |
| Grant date | Jan 23, 2001 |
| Priority date | — |
| Expiry date | Mar 11, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/0008
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention provides an apparatus and method for locating a curvilinear symbol by generating a grey scale model of a segment of a curvilinear symbol and interpolating curvature at the segment's periphery; reflecting this segment around the axes of symmetry to generate a full size model; generating full resolution subfeature models; assigning coordinate axes weighting to each subfeature model x and y axis; defining tolerance thresholds for deviations from an idealized curvilinear symbol; searching a digitized image for shapes corresponding to the subfeature models; assigning weights to scores returned for positions found corresponding to the subfeature models; producing weighted positions combining both coordinate axis weighting and score weighting; computing a best fit for the image found; comparing the positions found to tolerance thresholds and discarding those positions outside the thresholds; substituting and weighting alternate positions found, if any, to compute the location of the curvilinear symbol from remaining positions within the threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.