Skip to main content
Log in

Visual word density-based nonlinear shape normalization method for handwritten Chinese character recognition

  • Original Paper
  • Published:
International Journal on Document Analysis and Recognition (IJDAR) Aims and scope Submit manuscript

Abstract

In handwritten Chinese character recognition, the performance of a system is largely dependent on the character normalization method. In this paper, a visual word density-based nonlinear normalization method is proposed for handwritten Chinese character recognition. The underlying rationality is that the density for each image pixel should be determined by the visual word around this pixel. Visual vocabulary is used for mapping from a visual word to a density value. The mapping vocabulary is learned to maximize the ratio of the between-class variation and the within-class variation. Feature extraction is involved in the optimization stage, hence the proposed normalization method is beneficial for the following feature extraction. Furthermore, the proposed method can be applied to some other image classification problems in which scene character recognition is tried in this paper. Experimental results on one constrained handwriting database (CASIA) and one unconstrained handwriting database (CASIA-HWDB1.1) demonstrate that the proposed method outperforms the start-of-the-art methods. Experiments on scene character databases chars74k and ICDAR03-CH show that the proposed method is promising for some image classification problems.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

Similar content being viewed by others

References

  1. Tsukumo, J., Tanaka, H.: Classification of handprinted Chinese characters using nonlinear normalization and correlation methods. In: Proceedings of the International Conference on Pattern Recognition, pp. 168–171 (1988)

  2. Yamada, H., Yamamoto, K., Saito, T.: A nonlinear normalization method for handprinted Kanji character recognition line density equalization. Pattern Recognit. 23(9), 1023–1029 (1990)

    Article  Google Scholar 

  3. Horiuchi, T., Haruki, R., Yamada, H., Yamamoto, K.: Two-dimensional extension of nonlinear normalization method using line density for character recognition.In: Proceedings of the International Conference on Document Analysis and Recognition, pp. 511–514 (1997)

  4. Liu, C.L., Marukawa, K.: Pseudo two dimensional shape normalization methods for handwritten Chinese character recognition. Pattern Recognit. 38(12), 2242–2255 (2005)

    Article  Google Scholar 

  5. Liu, C.L., Sako, H., Fujisawa, H.: Handwritten Chinese character recognition: alternatives to nonlinear normalization. In: Proceedings of the International Conference on Document Analysis and Recognition, pp. 524–528 (2003)

  6. Liu, C.L.: High accuracy handwritten Chinese character recognition using quadratic classifiers with discriminative feature extraction: In Proceedings of the International Conference on Pattern Recognition, pp. 942–945 (2006)

  7. Leung, K.C., Leung, C.H.: Recognition of handwritten Chinese characters by combining regularization, Fisher’s discriminant and distorted sample generation. In: Proceedings of the International Conference on Document Analysis and Recognition, pp.1026–1030 (2009)

  8. Gao, T.F., Liu, C.L.: High accuracy handwritten Chinese character recognition using LDA-based compound distances. Pattern Recognit. 41(11), 3442–3451 (2008)

    Article  MATH  Google Scholar 

  9. Liu, C.L., Fujisawa, H.: Classification and learning methods for character recognition: advances and remaining problems. In: Machine Learning in Document Analysis and Recognition, pp. 139–161 (2008)

  10. Kimura, F., Takashina, K., Tsuruoka, S., Miyake, Y.: Modified quadratic discriminant functions and the application to Chinese character recognition. IEEE Trans. Pattern Anal. Mach. Intell. 9(1), 149–153 (1987)

    Article  Google Scholar 

  11. Liu, C.L.: Handwritten Chinese character recognition: effects of shape normalization and feature extraction. In: Arabic and Chinese Handwriting Recognition, pp. 104–128 (2008)

  12. Liu, C.L.: Normalization-cooperated gradient feature extraction for handwritten character recognition. IEEE Trans. Pattern Anal. Mach. Intell. 29(8), 1465–1469 (2007)

    Article  Google Scholar 

  13. Yamashita, Y., Higuchi, K., Yamada, Y., Haga, Y.: Classification of handprinted Kanji characters by the structured segment matching method. Pattern Recognit. Lett. 1(5), 475–479 (1983)

    Article  Google Scholar 

  14. Casey, R.G.: Moment normalization of handprinted character. IBM J. Res. Dev. 14(5), 548–557 (1970)

    Article  MathSciNet  MATH  Google Scholar 

  15. Lee, S.W., Park, J.S., Tang, Y.: Performance evaluation of nonlinear shape normalization methods for the recognition of large-set handwritten characters. In: Proceedings of the International Conference on Document Analysis and Recognition, pp. 402–407 (1993)

  16. Liu, C.L., Nakashima, K., Sako, H., Fujisawa, H.: Handwritten digit recognition: investigation of normalization and feature extraction techniques. Pattern Recognit. 37(2), 265–279 (2004)

    Article  MATH  Google Scholar 

  17. Liu, C.L., Yin, F., Wang, D.H., Wang, Q.F.: Online and offline handwritten Chinese character recognition: benchmarking on new databases. Pattern Recognit. 46(1), 155–162 (2013)

    Article  MathSciNet  Google Scholar 

  18. Liu, C.L., Yin, F., Wang, D.H., Wang, Q.F.: CASIA online and offline Chinese handwriting databases. In: Proceedings of the International Conference on Document Analysis and Recognition, pp. 37–41 (2011)

  19. de Campos, T.E., Babu, B.R., Varma, M.: Character recognition in natural images. In: Proceedings of the International Conference on Computer Vision Theory and Applications (2009)

  20. Lucas, S.M., Panaretos, A., Sosa, L., Tang, A., Wong, S., Young, R.: ICDAR 2003 robust reading competitions. In: Proceedings of the International Conference on Document Analysis and Recognition, pp. 682–687 (2003)

  21. Cula, O.G., Dana, K.J.: Compact representation of bidirectional texture functions. In: Proceedings of the International Conference on Computer Vision and Pattern Recognition, pp.1041–1047 (2001)

  22. Varma, M., Zisserman, A.: Classifying images of materials: achieving viewpoint and illumination independence. In: Proceedings of the European Conference on Computer Vision, pp. 255–271 (2002)

  23. Dance, C., Willamowski, J., Fan, L., Bray, C., Csurka, G.: Visual categorization with bags of keypoints. In: Proceedings of the European Conference on Computer Vision (2004)

  24. Hooke, R., Jeeves, T.A.: Direct search solution of numerical and statistical problems. J. ACM 8(2), 212–229 (1961)

    Article  MATH  Google Scholar 

  25. Torczon, V.: On the convergence of pattern search algorithms. SIAM J. Optim. 7, 1–25 (1997)

    Article  MathSciNet  MATH  Google Scholar 

  26. Liu, C.L., Suen, C.Y.: A new benchmark on the recognition of handwritten Bangla and Farsi numeral characters. Pattern Recognit 42(12), 3287–3295 (2009)

    Article  MATH  Google Scholar 

  27. Newell, A.J., Griffin, L.D.: Multiscale histogram of oriented gradient descriptors for robust character recognition. In: Proceedings of the International Conference on Document Analysis and Recognition, pp. 1085–1089 (2011)

Download references

Acknowledgments

We would like to express our sincere appreciation to the anonymous reviewers for their insightful comments, which have greatly aided us in improving the quality of the paper. This work was supported by National Natural Science Foundation of China (60933010, 61172103, 60835001).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Chunheng Wang.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Shao, Y., Wang, C. & Xiao, B. Visual word density-based nonlinear shape normalization method for handwritten Chinese character recognition. IJDAR 16, 387–397 (2013). https://doi.org/10.1007/s10032-012-0198-4

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10032-012-0198-4

Keywords

Navigation