Image analysis – Image enhancement or restoration – Object boundary expansion or contraction
Patent
1996-05-30
1998-11-10
Shalwala, Bipin
Image analysis
Image enhancement or restoration
Object boundary expansion or contraction
382170, 382204, 382219, G06K 942, G06K 944, G06K 946, G06K 968
Patent
active
058356380
ABSTRACT:
A method and apparatus for comparing symbols extracted from binary images of text for classifying into equivalence classes. The present invention uses a Hausdorff-like method for comparing symbols for similarity. When a symbol contained in a bitmap A is compared to a symbol contained in a bitmap B, it is determined whether or not the symbol in bitmap B fits within a tolerance into a dilated representation of the symbol in bitmap A with no excessive density of errors and whether the symbol in bitmap A fits within a tolerance into a dilated representation of the symbol in bitmap B with no excessive density of errors. If both tests are passed, an error density check is performed to determine a match. The dilated representation of the bitmap accounts for various quantization errors that may occur along the boundaries of a symbol defined in the respective bitmaps. The dilation utilized preserves the topology of the symbol. The topology preserving dilation is one where symbols are "thickened" yet the local topology (or connectedness) of the symbol is not changed. Such a dilation is performed by applying a set of local rules to "off" pixels that are adjacent to "on" pixels. Quantization effects are also accounted for through the use of a non-linear error allowance. The non-linear error allowance implements the idea that small symbols provide for little or no error, whereas large symbols provide for a proportionately larger amount of error.
REFERENCES:
patent: 2905927 (1959-09-01), Reed
patent: 3133266 (1964-05-01), Frishkopf
patent: 3295105 (1966-12-01), Gray et al.
patent: 4010445 (1977-03-01), Hoshino
patent: 4155072 (1979-05-01), Kawa
patent: 4326190 (1982-04-01), Borland et al.
patent: 4400828 (1983-08-01), Pirz et al.
patent: 4410916 (1983-10-01), Pratt et al.
patent: 4495644 (1985-01-01), Parks et al.
patent: 4558461 (1985-12-01), Schlang
patent: 4641356 (1987-02-01), Sternberg
patent: 4701960 (1987-10-01), Scott
patent: 4731857 (1988-03-01), Tappert
patent: 4764972 (1988-08-01), Yoshida et al.
patent: 4769716 (1988-09-01), Casey et al.
patent: 4809344 (1989-02-01), Peppers et al.
patent: 4864628 (1989-09-01), Scott
patent: 4918740 (1990-04-01), Ross
patent: 4926490 (1990-05-01), Mano
patent: 4933977 (1990-06-01), Ohnishi et al.
patent: 4949281 (1990-08-01), Hillenbrand et al.
patent: 4949392 (1990-08-01), Barski et al.
patent: 4956869 (1990-09-01), Miyatake
patent: 4977603 (1990-12-01), Irie et al.
patent: 5142589 (1992-08-01), Lougheed et al.
patent: 5214719 (1993-05-01), Budd et al.
patent: 5216725 (1993-06-01), McCubbrey
patent: 5303313 (1994-04-01), Mark et al.
patent: 5539841 (1996-07-01), Huttenlocher et al.
Arkin, E.M., Chew, L.P., Huttenlocker, D.P., Kedem, K., and Mitchell, J.S.B., "An Efficiently Computable Metric for Comparing Polygonal Shapes", in Proceedings of the First Annual ACMSIAM Symposium On Discrete Algorithms, San Francisco, California, Jan. 22-24, 1990., pp. 129-137.
Holt, M.J.J., and Xydeas, C.S., "Compression of Document Image Data by Symbol Matching", Department of EEE Loughborough Univ. of Technology, England, 1986, pp. 184-190.
Sato, J., Kuwamura, Y., and Ohno, C., "F6365 Japanese Document Reader," Fujitsu Sci. Tech. J., Oct. 1990, pp. 224-233.
Huttenlocker, D.P., Klanderman, G.A., and Rucklidge, W.J., "Comparing Images Using the Hausdorff Distance," Department of Computer Science, Cornell University, Ithica, NY, CUCS TR 91-1211, Abstract, pp. 1-34.
Huttenlocker, D.P., and Rucklidge, W.J., "A Multi-Resolution Technique for Comparing Images Using the Hausdorff Distance," Department of Computer Science, Cornell University, Ithica, NY, TR 92-1321, Dec. 1992, Abstract, pp. 1-20.
Huttenlocher Daniel P.
Jaquith Eric W.
Rucklidge William James
Domingo Richard B.
Shalwala Bipin
Xerox Corporation
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