Image analysis – Histogram processing – For setting a threshold
Patent
1983-03-14
1986-07-29
Boudreau, Leo H.
Image analysis
Histogram processing
For setting a threshold
382 25, 358260, G06K 950
Patent
active
046034315
ABSTRACT:
An apparatus codes a scanned document locally representing each graphic element within a prescribed measure of accuracy by a trapezoidal approximation. The invention also includes a method for similarly coding a scanned document. The apparatus determines whether each scanned run is indicative of a Y- or .lambda.-junction, the termination of an old, or the commencement of a new graphic element, and whether a new linear approximation is necessary. The invention in a preferred embodiment recognizes symbols by determining the center of mass and maximum extremity of a symbol candidate, and comparing it to a reference library after normalizing with respect to scale, orientation and center of mass. In a preferred embodiment, an adaptive threshold parameter governs coding so as to reject noise and optimize a pair of linear predicters in a small number of scans. In a further preferred embodiment the accuracy of the linear predicters is refined so that the error is exponentially bounded.
REFERENCES:
patent: 3347981 (1967-10-01), Kagan et al.
patent: 3422419 (1969-01-01), Mathews et al.
patent: 3521241 (1970-07-01), Rumble
patent: 3801737 (1974-04-01), Komura
patent: 3830964 (1974-08-01), Spencer
patent: 3937871 (1976-02-01), Robinson
patent: 3956580 (1976-05-01), Murayama
patent: 3992572 (1976-11-01), Nakagome
patent: 4103287 (1978-07-01), Frank
patent: 4107648 (1978-08-01), Frank
patent: 4189711 (1980-02-01), Frank
patent: 4193096 (1980-03-01), Stoffel
patent: 4213154 (1980-07-01), Ono
patent: 4307377 (1981-12-01), Pferd
patent: 4368462 (1983-01-01), Crawley
patent: 4410916 (1983-10-01), Pratt et al.
Kurozumi, "Polygonal Approximation by the Minimax Method", Computer Graphics & Image Processing, vol. 19, No. 3, Jul. 1982, pp. 248-264.
K. Ramachandran, "Coding Method for Vector Representation of Engineering Drawings," Proceedings of the IEEE, vol. 68, No. 7, (Jul. 1980), pp. 813-817, esp. p. 814, col. 2, p. 816.
Grover David N.
Kleca Eugene A.
Lipkie Curtis A.
ANA Tech Corporation
Boudreau Leo H.
LandOfFree
Method and apparatus for vectorizing documents and symbol recogn does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for vectorizing documents and symbol recogn, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for vectorizing documents and symbol recogn will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-703004