Abstract
In contrast to the field of automatic speech recognition where Markov model-based methods currently represent the state-of-the-art, HMMs and n-gram models are still a rather new approach for the recognition of machine-printed or handwritten texts. In this chapter we will present state-of-the-art systems for offline handwriting recognition. In addition to explanations of how Markov model technology is applied, these presentations will also include brief descriptions of the specialized methods for preprocessing and feature extraction used.
The first system presented in this chapter is BBN’s offline HWR system. It can be considered as a typical example for an HMM-based system for the recognition of machine-printed or handwritten script. Afterwards, we will present the offline HWR system of RWTH Aachen University, Aachen, Germany. The chapter concludes with a presentation of our own systems for offline handwriting recognition which include a system based on so-called Bag-of-Features HMMs. This recently proposed extension of the HMM framework works especially well on the challenging task of query-by-example word spotting.
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Notes
- 1.
Abbreviation for dots per inch.
- 2.
According to [159] no size or height normalization of the line images is performed.
- 3.
This size normalization operation is script dependent. For Roman script the implicit assumption that average character width is correlated with the average distances between contour minima is justified quite well. In contrast, for Arabic script this size normalization technique does not produce useful results.
- 4.
In [317] lexicon free experiments are reported for bi-gram up to 5-gram models.
References
Basha Shaik, M.A., Rybach, D., Hahn, S., Schlüter, R., Ney, H.: Hierarchical hybrid language models for open vocabulary continuous speech recognition using wfst. In: Proc. Workshop on Statistical and Perceptual Audition, Portland, OR, USA, pp. 46–51 (2012)
Bazzi, I., Schwartz, R., Makhoul, J.: An omnifont open-vocabulary OCR system for English and Arabic. IEEE Trans. on Pattern Analysis and Machine Intelligence 21(6), 495–504 (1999)
Caesar, T., Gloger, J.M., Mandler, E.: Preprocessing and feature extraction for a handwriting recognition system. In: Proc. Int. Conf. on Document Analysis and Recognition, Tsukuba Science City, Japan, pp. 408–411 (1993)
Colthurst, T., Kimball, O., Richardson, F., Shu, H., Wooters, C., Iyer, R., Gish, H.: The 2000 BBN Byblos LVCSR system. In: 2000 Speech Transcription Workshop, Maryland (2000)
Dolfing, J.G.A., Haeb-Umbach, R.: Signal representations for Hidden Markov Model based on-line handwriting recognition. In: Proc. Int. Conf. on Acoustics, Speech, and Signal Processing, München, vol. IV, pp. 3385–3388 (1997)
Dreuw, P., Jonas, S., Ney, H.: White-space models for offline Arabic handwriting recognition. In: Proc. Int. Conf. on Pattern Recognition, Tampa, FL, USA, pp. 1–4 (2008)
Dreuw, P., Rybach, D., Heigold, G., Ney, H.: Rwth ocr: a large vocabulary optical character recognition system for Arabic scripts. In: Märgner, V., El Abed, H. (eds.) Guide to OCR for Arabic Scripts, pp. 215–254. Springer, London, UK (2012). Chap. Part II: Recognition
Fei-Fei, L., Perona, P.: A Bayesian hierarchical model for learning natural scene categories. In: Proc. IEEE Comp. Soc. Conf. on Computer Vision and Pattern Recognition, vol. 2, pp. 524–531 (2005)
Fink, G.A., Plötz, T.: On appearance-based feature extraction methods for writer-independent handwritten text recognition. In: Proc. Int. Conf. on Document Analysis and Recognition, Seoul, Korea, vol. 2, pp. 1070–1074 (2005)
Fink, G.A., Plötz, T.: Unsupervised estimation of writing style models for improved unconstrained off-line handwriting recognition. In: Proc. Int. Workshop on Frontiers in Handwriting Recognition, La Baule, France, pp. 429–434 (2006)
Fink, G.A., Plötz, T.: On the use of context-dependent modelling units for HMM-based offline handwriting recognition. In: Proc. Int. Conf. on Document Analysis and Recognition, Curitiba, Brazil, vol. 2, pp. 729–733 (2007)
Fink, G.A., Vajda, S., Bhattacharya, U., Parui, S.K., Chaudhuri, B.B.: Online Bangla word recognition using sub-stroke level features and hidden Markov models. In: Proc. Int. Conf. on Frontiers in Handwriting Recognition, Kolkata, India, pp. 393–398 (2010)
Fink, G.A., Wienecke, M.: Experiments in video-based whiteboard reading. In: First Int. Workshop on Camera-Based Document Analysis and Recognition, Seoul, Korea, pp. 95–100 (2005)
Fink, G.A., Wienecke, M., Sagerer, G.: Video-based on-line handwriting recognition. In: Proc. Int. Conf. on Document Analysis and Recognition, pp. 226–230. IEEE, Seattle (2001)
Fischer, A., Keller, A., Frinken, V., Bunke, H.: Lexicon-free handwritten word spotting using character hmms. Pattern Recognit. Lett. 33(7), 934–942 (2012)
Grzeszick, R., Rothacker, L., Fink, G.A.: Bag-of-features representations using spatial visual vocabularies for object classification. In: IEEE Intl. Conf. on Image Processing, Melbourne, Australia (2013)
Hammerla, N.Y., Plötz, T., Vajda, S., Fink, G.A.: Towards feature learning for HMM-based offline handwriting recognition. In: International Workshop on Frontiers of Arabic Handwriting Recognition, Istanbul, Turkey (2010)
Kozielski, M., Doetsch, P., Ney, H.: Improvements in RWTH’s system for off-line handwriting recognition. In: Proc. Int. Conf. on Document Analysis and Recognition, Washington, DC, USA (2013)
Lazebnik, S., Schmid, C., Ponce, J.: Beyond bags of features: spatial pyramid matching for recognizing natural scene categories. In: Proc. IEEE Comp. Soc. Conf. on Computer Vision and Pattern Recognition, vol. 2, pp. 2169–2178 (2006)
Lowe, D.: Distinctive image features from scale-invariant keypoints. Int. J. Comput. Vis. 60(2), 91–110 (2004)
Lu, Z., Schwartz, R., Raphael, C.: Script-independent, HMM-based text line finding for OCR. In: Proc. Int. Conf. on Pattern Recognition, Barcelona, vol. 4, pp. 551–554 (2000)
Madhvanath, S., Kim, G., Govindaraju, V.: Chaincode contour processing for handwritten word recognition. IEEE Trans. Pattern Anal. Mach. Intell. 21(9), 928–932 (1999)
Marti, U.-V., Bunke, H.: Handwritten sentence recognition. In: Proc. Int. Conf. on Pattern Recognition, Barcelona, vol. 3, pp. 467–470 (2000)
Natarajan, P., Lu, Z., Schwartz, R., Bazzi, I., Makhoul, J.: Multilingual machine printed OCR. Int. J. Pattern Recognit. Artif. Intell. 15(1), 43–63 (2001)
Natarajan, P., Saleem, S., Prasad, R., MacRostie, E., Subramanian, K.: Multi-lingual offline handwriting recognition using hidden Markov models: a script-independent approach. In: Doermann, D.S., Jaeger, S. (eds.) SACH 2006: Arabic and Chinese Handwriting Recognition. Lecture Notes in Computer Science, vol. 4768, pp. 231–250. Springer, Berlin (2008)
O’Hara, S., Draper, B.A.: Introduction to the bag of features paradigm for image classification and retrieval. Comput. Res. Repository (2011). arXiv:1101.3354v1
Plötz, T., Fink, G.A.: Markov Models for Handwriting Recognition. Springer Briefs in Computer Science. Springer, Berlin (2011)
Plötz, T., Thurau, C., Fink, G.A.: Camera-based whiteboard reading: new approaches to a challenging task. In: Proc. Int. Conf. on Frontiers in Handwriting Recognition, Montreal, Canada, pp. 385–390 (2008)
Prasad, R., Saleem, S., Kamali, M., Meermeier, R., Natarajan, P.: Improvements in hidden Markov model based Arabic OCR. In: Proc. Int. Conf. on Pattern Recognition, pp. 1–4 (2008)
Rothacker, L., Fink, G.A., Banerjee, P., Bhattacharya, U., Chaudhuri, B.B.: Bag-of-features hmms for segmentation-free bangla word spotting. In: International Workshop on Multilingual OCR (MOCR), Washington DC, USA (2013)
Rothacker, L., Rusinol, M., Fink, G.A.: Bag-of-features HMMs for segmentation-free word spotting in handwritten documents. In: Proc. Int. Conf. on Document Analysis and Recognition, Washington DC, USA (2013)
Rothacker, L., Vajda, S., Fink, G.A.: Bag-of-features representations for offline handwriting recognition applied to Arabic script. In: Proc. Int. Conf. on Frontiers in Handwriting Recognition, Bari, Italy (2012)
Rusiñol, M., Aldavert, D., Toledo, R., Llados, J.: Browsing heterogeneous document collections by a segmentation-free word spotting method. In: Proc. Int. Conf. on Document Analysis and Recognition, Bejing, China, pp. 63–67 (2011)
Saleem, S., Cao, H., Subramanian, K., Kamali, M., Prasad, R., Natarajan, P.: Improvements in bbn’s hmm-based offline Arabic handwriting recognition system. In: Proc. Int. Conf. on Document Analysis and Recognition, pp. 773–777 (2009)
Salton, G., McGill, J.M.: Introduction to Modern Information Retrieval. McGraw-Hill, New York (1983)
Schwartz, R., LaPre, C., Makhoul, J., Raphael, C., Zhao, Y.: Language-independent OCR using a continuous speech recognition system. In: Proc. Int. Conf. on Pattern Recognition, Vienna, Austria, vol. 3, pp. 99–103 (1996)
Sivic, J., Zisserman, A.: Video Google: a text retrieval approach to object matching in videos. In: Proc. Int. Conf. on Computer Vision, vol. 2, pp. 1470–1477 (2003)
Wienecke, M., Fink, G.A., Sagerer, G.: Towards automatic video-based whiteboard reading. In: Proc. Int. Conf. on Document Analysis and Recognition, Edinburgh, Scotland, pp. 87–91 (2003)
Wienecke, M., Fink, G.A., Sagerer, G.: Toward automatic video-based whiteboard reading. Int. J. Doc. Anal. Recognit. 7(2–3), 188–200 (2005)
Zhang, Z., Tan, C.L.: Restoration of images scanned from thick bound documents. In: Int. Conf. on Image Processing, Thessaloniki, Greece, October 2001, pp. 1074–1077 (2001)
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Fink, G.A. (2014). Handwriting Recognition. In: Markov Models for Pattern Recognition. Advances in Computer Vision and Pattern Recognition. Springer, London. https://doi.org/10.1007/978-1-4471-6308-4_14
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