A Constrained Approach to Multifont Chinese Character Recognition
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The constraint graph is introduced as a general character representation framework for recognizing multifont, multiple-size Chinese characters. Each character class is described by a constraint graph model. Sampling points on a character skeleton are taken as nodes in the graph. Connection constraints and position constraints are taken as arcs in the graph. For patterns of the same character class, the model captures both the topological invariance and the geometrical invariance in a general and uniform way. Character recognition is then formulated as a constraint-based optimization problem. A cooperative relaxation matching algorithm that solves this optimization problem is developed. A practical optical character recognition (OCR) system that is able to recognize multifont, multiple-size Chinese characters with a satisfactory performance was implemented.
[1] 838G. L. Cash and M. Hatamian, "Optical character recognition by the method of moments,"Comput. Vision Graphics Image Processing, vol. 39, pp. 291-310, 1987.
[2] L. H. Chen and J. R. Lieh, "Handwritten character recognition using a 2-layer random graph by relaxation matching,"Comput. Vision Graphics Image Processing, vol. 23, no. 11, pp. 1189-1205, 1990.
[3] F. -H. Cheng, W. -H. Hsu, and M. -Y. Chen, "Recognition of handwritten chinese characters by modified hough transform techniques,"IEEE Trans. Patt. Anal. Machine Intell., vol. 11. no. 4, pp. 429-439, Apr. 1989.
[4] Y. Le Cunet al., "Constrained neural network for unconstrained handwritten git recognition," inProc. Frontiers Handwritten Recogn., 1990, pp. 145-151.
[5] K.S. Fu, "A step towards unification of syntactic and statistical pattern recognition,"IEEE Trans. Patt. Anal. Machine Intell., vol. PAMI-8, no. 3, 1986.
[6] K. Fukunaga,Introduction to Statistical Pattern Recognition. New York: Academic, 1972.
[7] K. W. Gan and K. T. Lua, "Chinese character classification using an adaptive resonance network,"Patt. Recogn., vol. 25, no. 8, pp. 877-882, 1991.
[8] V. K. Govindan, "Character recognition--A review,"Patt. Recogn., vol. 23. no. 7, pp. 671-683, 1990.
[9] J. Gu,Constraint-Based Search. New York: Cambridge University Press, to be published.
[10] J. S. Huang and M. L. Chung, "Separating similar complex chinese characters by Walsh transform,"Patt. Recogn., vol. 20, no. 4, pp. 425-528, 1987.
[11] S. Kahan, T. Pavlidis, and H. S. Baird, "On the recognition of printed characters of any font and size,"IEEE Trans. Patt. Anal. Machine Intell., vol. PAMI-9, pp. 274-288, 1987.
[12] A. Krzyzak, W. Dai, and C. Y. Suen, "'Unconstrained handwritten classification using modified backpropagation model," inProc. Frontiers Handwritten Recogn., 1990, pp. 155-164.
[13] A. Kundu, Y. He, and P. Bahl, "Recognition of handwritten word: First and second order hidden Markov model based approach,"Patt. Recognition, vol. 22, no. 3, pp. 283-297, 1989.
[14] C. H. Leung, "Structural matching using neural networks," inAbstracts of the First Annual INNS Meeting, 1988, pp. 31.
[15] S. Mori, C. Y. Suen, and K. Yamamoto, "Historical review of ocr research and development,"Proc. IEEE, vol. 80, no. 7, pp. 1029-1058, July 1992.
[16] N. M. Nasrabadi and W. Li, "Object recognition by a hopfield neural network,"IEEE Trans. Syst. Man Cybern., vol. 21, no. 6, pp. 1523-1535, Nov./Dec. 1991.
[17] J. C. Simon, A. Checroun, and C. Roche, "A method of comparing two patterns independent of possible transformations and small distortions,"Patt. Recogn., vol. 4, no. 1, pp. 73-81, Jan. 1972.
[18] S. L. Xie and M. Suk, "On machine recognition of hand-printed Chinese characters by feature relaxation,"Patt. Recogn., vol. 21, no. 1, pp. 1-7, 1988.
Index Terms:
connection constraints; sampling points; multifont Chinese character recognition; constraint graph; character skeleton; position constraints; topological invariance; geometrical invariance; constraint-based optimization; cooperative relaxation matching algorithm; OCR; character recognition; graph theory; optimisation; topology
Citation:
X. Huang, J. Gu, Y. Wu, "A Constrained Approach to Multifont Chinese Character Recognition," IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 15, no. 8, pp. 838-843, Aug. 1993, doi:10.1109/34.236243