Method and apparatus for similarity matching of handwritten data objects
US5710916A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 1995 |
| Grant date | Jan 20, 1998 |
| Priority date | — |
| Expiry date | Jun 16, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99939
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Apparatus for determining a distance between two handwritten strings in a database. A processor extracts global features from each string. The processor divides the string into strokes, and identifies a plurality of bounding boxes. Each box contains a different stroke. The processor extracts global features from the suing, including: (1) a number of points; (2) a maximum angle between a first point in the string and a corner of the tallest bounding box; (3) a number of positive inversions; and (4) a number of negative inversions. The apparatus calculates the distance between the strings based on all of the numbers of points, maximum angles, numbers of positive inversions and numbers of negative inversions. A fixed query tree index may be formed. The tree has leaves and internal nodes belonging to multiple levels. A different key is associated with each level. Each key is a handwritten string. Each string is associated with one of the leaves, such that each child of each internal node in any of the levels between the one leaf and the root node is a root of a respective subtree. Each string associated with any leaf in the subtree which includes the one leaf is equally distant from th…
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