On-line adaptation in recognition of handwritten alphanumeric characters

We have developed an adaptive online recognizer that is suitable for recognizing isolated alphanumeric characters. It is based on the k nearest neighbor rule. Various dissimilarity measures, all based on dynamic time warping (DTW), have been studied. The main focus of this work is on online adaptation. The adaptation is performed by modifying the prototype set of the classifier according to its recognition performance and the user's writing style. These adaptations include: (1) adding new prototypes, (2) inactivating confusing prototypes, and (3) reshaping existing prototypes. The reshaping algorithm is based on learning vector quantization (LVQ). The writers are allowed to use their own natural style of writing, and the adaptation is carried out during normal use in a self-supervised fashion and thus remains otherwise unnoticed by the user.

[1]  Shane S. Sturrock,et al.  Time Warps, String Edits, and Macromolecules – The Theory and Practice of Sequence Comparison . David Sankoff and Joseph Kruskal. ISBN 1-57586-217-4. Price £13.95 (US$22·95). , 2000 .

[2]  Peter E. Hart,et al.  The condensed nearest neighbor rule (Corresp.) , 1968, IEEE Trans. Inf. Theory.

[3]  Ulric Neisser,et al.  A Note on Human Recognition of Hand-Printed Characters , 1960, Inf. Control..

[4]  Hiroki Arakawa.  On-line recognition of handwritten characters - alphanumerics, Hiragana, Katakana, Kanji , 1983, Pattern Recognit..

[5]  Erkki Oja,et al.  Adaptation of Prototype Sets in On-line Recognition of Isolated Handwritten Latin Characters , 1999 .

[6]  Erkki Oja,et al.  Comparison of Adaptive Strategies for On-Line Character Recognition , 1998 .

[7]  Clive Frankish,et al.  Recognition accuracy and user acceptance of pen interfaces , 1995, CHI '95.

[8]  David Sankoff,et al.  Time Warps, String Edits, and Macromolecules: The Theory and Practice of Sequence Comparison , 1983 .

[9]  Isabelle Guyon,et al.  UNIPEN project of on-line data exchange and recognizer benchmarks , 1994, Proceedings of the 12th IAPR International Conference on Pattern Recognition, Vol. 3 - Conference C: Signal Processing (Cat. No.94CH3440-5).

[10]  Charles C. Tappert.  Speed, Accuracy, and Flexibility Trade-Offs in on-Line Character Recognition , 1991, Int. J. Pattern Recognit. Artif. Intell..

[11]  J. L. Hodges,et al.  Discriminatory Analysis - Nonparametric Discrimination: Consistency Properties , 1989 .

[12]  C. G. Hilborn,et al.  The Condensed Nearest Neighbor Rule , 1967 .

[13]  Marc Parizeau,et al.  Machine vs humans in a cursive script reading experiment without linguistic knowledge , 1994, Proceedings of the 12th IAPR International Conference on Pattern Recognition, Vol. 3 - Conference C: Signal Processing (Cat. No.94CH3440-5).