A Web-Based Demo to Interactive Multimodal Transcription of Historic Text images

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-04346-8_58[EN] Paleography experts spend many hours transcribing historic documents, and state-of-the-art handwritten text recognition systems are not suitable for performing this task automatically. In this paper we present the modifications oil a previously developed interactive framework for transcription of handwritten text. This system, rather than full automation, aimed at assisting the user with the recognition-transcription process.This work has been supported by the EC (FEDER), the Spanish MEC under grant TIN2006-15694-C02-01 and the research programme Consolider Ingenio 2010 MIPRCV (CSD2007-00018) and by the UPV (FPI fellowship 2006-04).Romero Gómez, V.; Leiva Torres, LA.; Alabau Gonzalvo, V.; Toselli, AH.; Vidal Ruiz, E. (2009). A Web-Based Demo to Interactive Multimodal Transcription of Historic Text images. En Research and Advanced Technology for Digital Libraries: 13th European Conference, ECDL 2009, Corfu, Greece, September 27 - October 2, 2009. Proceedings. Springer Verlag (Germany). 459-460. https://doi.org/10.1007/978-3-642-04346-8_58S459460Toselli, A.H., et al.: Computer assisted transcription of handwritten text. In: Proc. of ICDAR 2007, pp. 944–948. IEEE Computer Society, Los Alamitos (2007)Romero, V., Toselli, A.H., Rodríguez, L., Vidal, E.: Computer assisted transcription for ancient text images. In: Kamel, M.S., Campilho, A. (eds.) ICIAR 2007. LNCS, vol. 4633, pp. 1182–1193. Springer, Heidelberg (2007)Toselli, A.H., et al.: Computer assisted transcription of text images and multimodal interaction. In: Popescu-Belis, A., Stiefelhagen, R. (eds.) MLMI 2008. LNCS, vol. 5237, pp. 296–308. Springer, Heidelberg (2008)Romero, V.: et al.: Interactive multimodal transcription of text images using a web-based demo system. In: Proc. of the IUI, Florida, pp. 477–478 (2009)Romero, V., et al.: Improvements in the computer assisted transciption system of handwritten text images. In: Proc. of the PRIS 2008, pp. 103–112 (2008

On the optimal decision rule for sequential interactive structured prediction

This is the author’s version of a work that was accepted for publication in Pattern Recognition Letters. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Pattern Recognition Letters [Volume 33, Issue 16, 1 December 2012, Pages 2226–2231] DOI: 10.1016/j.patrec.2012.07.010[EN] Interactive structured prediction (ISP) is an emerging framework for structured prediction (SP) where the user and the system collaborate to produce a high quality output. Typically, search algorithms applied to ISP problems have been based on the algorithms for fully-automatic SP systems. However, the decision rule applied should not be considered as optimal since the goal in ISP is to reduce human effort instead of output errors. In this work, we present some insight into the theory of the sequential ISP search problem. First, it is formulated as a decision theory problem from which a general analytical formulation of the opti- mal decision rule is derived. Then, it is compared with the standard formulation to establish under what conditions the standard algorithm should perform similarly to the optimal decision rule. Finally, a general and practical implementation is given and evaluated against three classical ISP problems: interactive machine translation, interactive handwritten text recognition, and interactive speech recognition.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under Grant agreement no. 287576 (CasMaCat), and from the Spanish MEC/MICINN under the MIPRCV "Consolider Ingenio 2010" program (CSD2007-00018) and iTrans2 (TIN2009-14511) project. It is also supported by the Generalitat Valenciana under grant ALMPR (Prometeo/2009/01) and GV/2010/067. The authors thank the anonymous reviewers for their criticisms and suggestions.Alabau, V.; Sanchis Navarro, JA.; Casacuberta Nolla, F. (2012). On the optimal decision rule for sequential interactive structured prediction. Pattern Recognition Letters. 33(16):2226-2231. https://doi.org/10.1016/j.patrec.2012.07.010S22262231331

Implementation of a Human-Computer Interface for Computer Assisted Translation and Handwritten Text Recognition

A human-computer interface is developed to provide services of computer assisted machine translation (CAT) and computer assisted transcription of handwritten text images (CATTI). The back-end machine translation (MT) and handwritten text recognition (HTR) systems are provided by the Pattern Recognition and Human Language Technology (PRHLT) research group. The idea is to provide users with easy to use tools to convert interactive translation and transcription feasible tasks. The assisted service is provided by remote servers with CAT or CATTI capabilities. The interface supplies the user with tools for efficient local edition: deletion, insertion and substitution.Ocampo Sepúlveda, JC. (2009). Implementation of a Human-Computer Interface for Computer Assisted Translation and Handwritten Text Recognition. http://hdl.handle.net/10251/14318Archivo delegad

An iterative multimodal framework for the transcription of handwritten historical documents

[EN] The transcription of historical documents is one of the most interesting tasks in which Handwritten Text Recognition can be applied, due to its interest in humanities research. One alternative for transcribing the ancient manuscripts is the use of speech dictation by using Automatic Speech Recognition techniques. In the two alternatives similar models (Hidden Markov Models and n-grams) and decoding processes (Viterbi decoding) are employed, which allows a possible combination of the two modalities with little diffi- culties. In this work, we explore the possibility of using recognition results of one modality to restrict the decoding process of the other modality, and apply this process iteratively. Results of these multimodal iterative alternatives are significantly better than the baseline uni-modal systems and better than the non-iterative alternatives. 2012 Elsevier B.V. All rights reserved.Work supported by the EC (FEDER/FSE) and the Spanish MEC/MICINN under the MIPRCV ’’Consolider Ingenio 2010’’ program (CSD2007-00018), iTrans2 (TIN2009–14511) and MITTRAL (TIN2009-14633-C03–01) projects. Also supported by the Spanish MITyC under the erudito.com (TSI-020110-2009-439) project and by the Generalitat Valenciana under grant GV/2010/067, and by the UPV under project PAID-05-11-2779 and grant UPV/2009/2851.Alabau, V.; Martínez Hinarejos, CD.; Romero Gómez, V.; Lagarda Arroyo, AL. (2014). An iterative multimodal framework for the transcription of handwritten historical documents. Pattern Recognition Letters. 35:195-203. https://doi.org/10.1016/j.patrec.2012.11.007S1952033

Word-Graph Based Applications for Handwriting Documents: Impact of Word-Graph Size on Their Performances

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-19390-8 29Computer Assisted Transcription of Text Images (CATTI) and Key-Word Spotting (KWS) applications aim at transcribing and indexing handwritten documents respectively. They both are approached by means of Word Graphs (WG) obtained using segmentation-free handwritten text recognition technology based on N-gram Language Models and Hidden Markov Models. A large WG contains most of the relevant information of the original text (line) image needed for CATTI and KWS but, if it is too large, the computational cost of generating and using it can become unaffordable. Conversely, if it is too small, relevant information may be lost, leading to a reduction of CATTI/KWS in performance accuracy. We study the trade-off between WG size and CATTI &KWS performance in terms of effectiveness and efficiency. Results show that small, computationally cheap WGs can be used without loosing the excellent CATTI/KWS performance achieved with huge WGs.Work partially supported by the Spanish MICINN projects STraDA (TIN2012-37475-C02-01) and by the EU 7th FP tranScriptorium project (Ref:600707).Toselli, AH.; Romero Gómez, V.; Vidal Ruiz, E. (2015). Word-Graph Based Applications for Handwriting Documents: Impact of Word-Graph Size on Their Performances. En Pattern Recognition and Image Analysis. Springer. 253-261. https://doi.org/10.1007/978-3-319-19390-8_29S253261Romero, V., Toselli, A.H., Vidal, E.: Multimodal Interactive Handwritten Text Transcription. Series in Machine Perception and Artificial Intelligence (MPAI). World Scientific Publishing, Singapore (2012)Toselli, A.H., Vidal, E., Romero, V., Frinken, V.: Word-graph based keyword spotting and indexing of handwritten document images. Technical report, Universitat Politècnica de València (2013)Oerder, M., Ney, H.: Word graphs: an efficient interface between continuous-speech recognition and language understanding. In: IEEE International Conference on Acoustics, Speech, and Signal Processing, vol. 2, pp. 119–122, April 1993Bazzi, I., Schwartz, R., Makhoul, J.: An omnifont open-vocabulary OCR system for English and Arabic. IEEE Trans. Pattern Anal. Mach. Intell. 21(6), 495–504 (1999)Jelinek, F.: Statistical Methods for Speech Recognition. MIT Press, Cambridge (1998)Ström, N.: Generation and minimization of word graphs in continuous speech recognition. In: Proceedings of IEEE Workshop on ASR 1995, Snowbird, Utah, pp. 125–126 (1995)Ortmanns, S., Ney, H., Aubert, X.: A word graph algorithm for large vocabulary continuous speech recognition. Comput. Speech Lang. 11(1), 43–72 (1997)Wessel, F., Schluter, R., Macherey, K., Ney, H.: Confidence measures for large vocabulary continuous speech recognition. IEEE Trans. Speech Audio Process. 9(3), 288–298 (2001)Robertson, S.: A new interpretation of average precision. In: Proceedings of the International ACM SIGIR Conference on Research and Development in Information Retrieval (SIGIR 2008), pp. 689–690. ACM, USA (2008)Manning, C.D., Raghavan, P., Schutze, H.: Introduction to Information Retrieval. Cambridge University Press, USA (2008)Romero, V., Toselli, A.H., Rodríguez, L., Vidal, E.: Computer assisted transcription for ancient text images. In: Kamel, M.S., Campilho, A. (eds.) ICIAR 2007. LNCS, vol. 4633, pp. 1182–1193. Springer, Heidelberg (2007)Fischer, A., Wuthrich, M., Liwicki, M., Frinken, V., Bunke, H., Viehhauser, G., Stolz, M.: Automatic transcription of handwritten medieval documents. In: 15th International Conference on Virtual Systems and Multimedia, VSMM 2009, pp. 137–142 (2009)Pesch, H., Hamdani, M., Forster, J., Ney, H.: Analysis of preprocessing techniques for latin handwriting recognition. In: ICFHR, pp. 280–284 (2012)Evermann, G.: Minimum Word Error Rate Decoding. Ph.D. thesis, Churchill College, University of Cambridge (1999

Word graphs size impact on the performance of handwriting document applications

[EN] Two document processing applications are con- sidered: computer-assisted transcription of text images (CATTI) and Keyword Spotting (KWS), for transcribing and indexing handwritten documents, respectively. Instead of working directly on the handwriting images, both of them employ meta-data structures called word graphs (WG), which are obtained using segmentation-free hand- written text recognition technology based on N-gram lan- guage models and hidden Markov models. A WG contains most of the relevant information of the original text (line) image required by CATTI and KWS but, if it is too large, the computational cost of generating and using it can become unafordable. Conversely, if it is too small, relevant information may be lost, leading to a reduction of CATTI or KWS performance. We study the trade-off between WG size and performance in terms of effectiveness and effi- ciency of CATTI and KWS. Results show that small, computationally cheap WGs can be used without loosing the excellent CATTI and KWS performance achieved with huge WGs.Work partially supported by the Generalitat Valenciana under the Prometeo/2009/014 Project Grant ALMAMATER, by the Spanish MECD as part of the Valorization and I+D+I Resources program of VLC/CAMPUS in the International Excellence Campus program, and through the EU projects: HIMANIS (JPICH programme, Spanish Grant Ref. PCIN-2015-068) and READ (Horizon-2020 programme, Grant Ref. 674943).Toselli ., AH.; Romero Gómez, V.; Vidal, E. (2017). Word graphs size impact on the performance of handwriting document applications. Neural Computing and Applications. 28(9):2477-2487. https://doi.org/10.1007/s00521-016-2336-2S24772487289Amengual JC, Vidal E (1998) Efficient error-correcting Viterbi parsing. IEEE Trans Pattern Anal Mach Intell 20(10):1109–1116Bazzi I, Schwartz R, Makhoul J (1999) An omnifont open-vocabulary OCR system for English and Arabic. IEEE Trans Pattern Anal Mach Intell 21(6):495–504Erman L, Lesser V (1990) The HEARSAY-II speech understanding system: a tutorial. Readings in Speech Reasoning, pp 235–245Evermann G (1999) Minimum word error rate decoding. Ph.D. thesis, Churchill College, University of CambridgeFischer A, Wuthrich M, Liwicki M, Frinken V, Bunke H, Viehhauser G, Stolz M (2009) Automatic transcription of handwritten medieval documents. In: 15th international conference on virtual systems and multimedia, 2009. VSMM ’09, pp 137–142Frinken V, Fischer A, Manmatha R, Bunke H (2012) A novel word spotting method based on recurrent neural networks. IEEE Trans Pattern Anal Mach Intell 34(2):211–224Furcy D, Koenig S (2005) Limited discrepancy beam search. In: Proceedings of the 19th international joint conference on artificial intelligence, IJCAI’05, pp 125–131Granell E, Martínez-Hinarejos CD (2015) Multimodal output combination for transcribing historical handwritten documents. In: 16th international conference on computer analysis of images and patterns, CAIP 2015, chap, pp 246–260. Springer International PublishingHakkani-Tr D, Bchet F, Riccardi G, Tur G (2006) Beyond ASR 1-best: using word confusion networks in spoken language understanding. Comput Speech Lang 20(4):495–514Jelinek F (1998) Statistical methods for speech recognition. MIT Press, CambridgeJurafsky D, Martin JH (2009) Speech and language processing: an introduction to natural language processing, speech recognition, and computational linguistics, 2nd edn. Prentice-Hall, Englewood CliffsKneser R, Ney H (1995) Improved backing-off for N-gram language modeling. In: International conference on acoustics, speech and signal processing (ICASSP ’95), vol 1, pp 181–184. IEEE Computer SocietyLiu P, Soong FK (2006) Word graph based speech recognition error correction by handwriting input. In: Proceedings of the 8th international conference on multimodal interfaces, ICMI ’06, pp 339–346. ACMLowerre BT (1976) The harpy speech recognition system. Ph.D. thesis, Pittsburgh, PALuján-Mares M, Tamarit V, Alabau V, Martínez-Hinarejos CD, Pastor M, Sanchis A, Toselli A (2008) iATROS: a speech and handwritting recognition system. In: V Jornadas en Tecnologías del Habla (VJTH’2008), pp 75–78Mangu L, Brill E, Stolcke A (2000) Finding consensus in speech recognition: word error minimization and other applications of confusion networks. Comput Speech Lang 14(4):373–400Manning CD, Raghavan P, Schutze H (2008) Introduction to information retrieval. Cambridge University Press, New YorkMohri M, Pereira F, Riley M (2002) Weighted finite-state transducers in speech recognition. Comput Speech Lang 16(1):69–88Odell JJ, Valtchev V, Woodland PC, Young SJ (1994) A one pass decoder design for large vocabulary recognition. In: Proceedings of the workshop on human language technology, HLT ’94, pp 405–410. Association for Computational LinguisticsOerder M, Ney H (1993) Word graphs: an efficient interface between continuous-speech recognition and language understanding. IEEE Int Conf Acoust Speech Signal Process 2:119–122Olivie J, Christianson C, McCarry J (eds) (2011) Handbook of natural language processing and machine translation. Springer, BerlinOrtmanns S, Ney H, Aubert X (1997) A word graph algorithm for large vocabulary continuous speech recognition. Comput Speech Lang 11(1):43–72Padmanabhan M, Saon G, Zweig G (2000) Lattice-based unsupervised MLLR for speaker adaptation. In: ASR2000-automatic speech recognition: challenges for the New Millenium ISCA Tutorial and Research Workshop (ITRW)Pesch H, Hamdani M, Forster J, Ney H (2012) Analysis of preprocessing techniques for latin handwriting recognition. In: International conference on frontiers in handwriting recognition, ICFHR’12, pp 280–284Povey D, Ghoshal A, Boulianne G, Burget L, Glembek O, Goel N, Hannemann M, Motlicek P, Qian Y, Schwarz P, Silovsky J, Stemmer G, Vesely K (2011) The Kaldi speech recognition toolkit. In: IEEE 2011 workshop on automatic speech recognition and understanding. IEEE Signal Processing SocietyPovey D, Hannemann M, Boulianne G, Burget L, Ghoshal A, Janda M, Karafiat M, Kombrink S, Motlcek P, Qian Y, Riedhammer K, Vesely K, Vu NT (2012) Generating Exact Lattices in the WFST Framework. In: IEEE international conference on acoustics, speech, and signal processing (ICASSP)Rabiner L (1989) A tutorial of hidden Markov models and selected application in speech recognition. Proc IEEE 77:257–286Robertson S (2008) A new interpretation of average precision. In: Proceedings of the international ACM SIGIR conference on research and development in information retrieval (SIGIR ’08), pp 689–690. ACMRomero V, Toselli AH, Rodríguez L, Vidal E (2007) Computer assisted transcription for ancient text images. Proc Int Conf Image Anal Recogn LNCS 4633:1182–1193Romero V, Toselli AH, Vidal E (2012) Multimodal interactive handwritten text transcription. Series in machine perception and artificial intelligence (MPAI). World Scientific Publishing, SingaporeRybach D, Gollan C, Heigold G, Hoffmeister B, Lööf J, Schlüter R, Ney H (2009) The RWTH aachen university open source speech recognition system. In: Interspeech, pp 2111–2114Sánchez J, Mühlberger G, Gatos B, Schofield P, Depuydt K, Davis R, Vidal E, de Does J (2013) tranScriptorium: an European project on handwritten text recognition. In: DocEng, pp 227–228Saon G, Povey D, Zweig G (2005) Anatomy of an extremely fast LVCSR decoder. In: INTERSPEECH, pp 549–552Strom N (1995) Generation and minimization of word graphs in continuous speech recognition. In: Proceedings of IEEE workshop on ASR’95, pp 125–126. Snowbird, UtahTanha J, de Does J, Depuydt K (2015) Combining higher-order N-grams and intelligent sample selection to improve language modeling for Handwritten Text Recognition. In: ESANN 2015 proceedings, European symposium on artificial neural networks, computational intelligence and machine learning, pp 361–366Toselli A, Romero V, i Gadea MP, Vidal E (2010) Multimodal interactive transcription of text images. Pattern Recogn 43(5):1814–1825Toselli A, Romero V, Vidal E (2015) Word-graph based applications for handwriting documents: impact of word-graph size on their performances. In: Paredes R, Cardoso JS, Pardo XM (eds) Pattern recognition and image analysis. Lecture Notes in Computer Science, vol 9117, pp 253–261. Springer International PublishingToselli AH, Juan A, Keysers D, Gonzlez J, Salvador I, Ney H, Vidal E, Casacuberta F (2004) Integrated handwriting recognition and interpretation using finite-state models. Int J Pattern Recogn Artif Intell 18(4):519–539Toselli AH, Vidal E (2013) Fast HMM-Filler approach for key word spotting in handwritten documents. In: Proceedings of the 12th international conference on document analysis and recognition (ICDAR’13). IEEE Computer SocietyToselli AH, Vidal E, Romero V, Frinken V (2013) Word-graph based keyword spotting and indexing of handwritten document images. Technical report, Universitat Politècnica de ValènciaUeffing N, Ney H (2007) Word-level confidence estimation for machine translation. Comput Linguist 33(1):9–40. doi: 10.1162/coli.2007.33.1.9Vinciarelli A, Bengio S, Bunke H (2004) Off-line recognition of unconstrained handwritten texts using HMMs and statistical language models. IEEE Trans Pattern Anal Mach Intell 26(6):709–720Weng F, Stolcke A, Sankar A (1998) Efficient lattice representation and generation. In: Proceedings of ICSLP, pp 2531–2534Wessel F, Schluter R, Macherey K, Ney H (2001) Confidence measures for large vocabulary continuous speech recognition. IEEE Trans Speech Audio Process 9(3):288–298Wolf J, Woods W (1977) The HWIM speech understanding system. In: IEEE international conference on acoustics, speech, and signal processing, ICASSP ’77, vol 2, pp 784–787Woodland P, Leggetter C, Odell J, Valtchev V, Young S (1995) The 1994 HTK large vocabulary speech recognition system. In: International conference on acoustics, speech, and signal processing (ICASSP ’95), vol 1, pp 73 –76Young S, Odell J, Ollason D, Valtchev V, Woodland P (1997) The HTK book: hidden Markov models toolkit V2.1. Cambridge Research Laboratory Ltd, CambridgeYoung S, Russell N, Thornton J (1989) Token passing: a simple conceptual model for connected speech recognition systems. Technical reportZhu M (2004) Recall, precision and average precision. Working Paper 2004–09 Department of Statistics and Actuarial Science, University of WaterlooZimmermann M, Bunke H (2004) Optimizing the integration of a statistical language model in hmm based offline handwritten text recognition. In: Proceedings of the 17th international conference on pattern recognition, 2004. ICPR 2004, vol 2, pp 541–54

Multimodal Interactive Transcription of Handwritten Text Images

En esta tesis se presenta un nuevo marco interactivo y multimodal para la transcripción de Documentos manuscritos. Esta aproximación, lejos de proporcionar la transcripción completa pretende asistir al experto en la dura tarea de transcribir. Hasta la fecha, los sistemas de reconocimiento de texto manuscrito disponibles no proporcionan transcripciones aceptables por los usuarios y, generalmente, se requiere la intervención del humano para corregir las transcripciones obtenidas. Estos sistemas han demostrado ser realmente útiles en aplicaciones restringidas y con vocabularios limitados (como es el caso del reconocimiento de direcciones postales o de cantidades numéricas en cheques bancarios), consiguiendo en este tipo de tareas resultados aceptables. Sin embargo, cuando se trabaja con documentos manuscritos sin ningún tipo de restricción (como documentos manuscritos antiguos o texto espontáneo), la tecnología actual solo consigue resultados inaceptables. El escenario interactivo estudiado en esta tesis permite una solución más efectiva. En este escenario, el sistema de reconocimiento y el usuario cooperan para generar la transcripción final de la imagen de texto. El sistema utiliza la imagen de texto y una parte de la transcripción previamente validada (prefijo) para proponer una posible continuación. Despues, el usuario encuentra y corrige el siguente error producido por el sistema, generando así un nuevo prefijo mas largo. Este nuevo prefijo, es utilizado por el sistema para sugerir una nueva hipótesis. La tecnología utilizada se basa en modelos ocultos de Markov y n-gramas. Estos modelos son utilizados aquí de la misma manera que en el reconocimiento automático del habla. Algunas modificaciones en la definición convencional de los n-gramas han sido necesarias para tener en cuenta la retroalimentación del usuario en este sistema.Romero Gómez, V. (2010). Multimodal Interactive Transcription of Handwritten Text Images [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8541Palanci

Language technology for handwritten text recognition

This paper shows how the nowadays prevalent technology used in HTR borrows concepts and methods from the field of ASR; i.e. those based on Hidden Markov Models (HMMs). Additionally, it will be described a HTR approach based on employing Bernoulli distributions rather than Gaussian-Mixture distributions for the HMM-state emission probability of observations. Finally, handwritten text recognition evaluation results are reported for several corpora involving different characteristics and languages.Work supported by the EC (FEDER), the Spanish MEC under the MIPRCV “Consolider Ingenio 2010” research programme (CSD2007- 00018) and the Spanisg Government (MICINN and “Plan E”) under the MITTRAL (TIN2009-14633-C03-01) research project.Toselli, AH.; Serrano Martínez-Santos, N.; Giménez Pastor, A.; Khoury, I.; Juan Císcar, A.; Vidal Ruiz, E. (2012). Language technology for handwritten text recognition. En Advances in Speech and Language Technologies for Iberian Languages. Springer Verlag (Germany). 328:178-186. https://doi.org/10.1007/978-3-642-35292-8_19S178186328Likforman-Sulem, L., Zahour, A., Taconet, B.: Text line segmentation of historical documents: a survey. International Journal on Document Analysis and Recognition 9, 123–138 (2007)Wong, K.Y., Wahl, F.M.: Document analysis system. IBM Journal of Research and Development 26, 647–656 (1982)Jelinek, F.: Statistical methods for speech recognition. MIT Press (1998)Katz, S.M.: Estimation of probabilities from sparse data for the language model component of a speech recognizer. In: Proceedings of the IEEE Transactions on Acoustics, Speech and Signal Processing (ICASSP 1987), vol. ASSP-35, pp. 400–401(March 1987)Kneser, R., Ney, H.: Improved backing-off for n-gram language modeling. In: Proceedings of the International Conference on Acoustics, Speech and Signal Processing (ICASSP), vol. 1, pp. 181–184 (1995)Bazzi, I., Schwartz, R., Makhoul, J.: An omnifont open-vocabulary OCR system for English and Arabic. IEEE Transactions on Pattern Analysis and Machine Intelligence 21(6), 495–504 (1999)Toselli, A.H., Juan, A., Keysers, D., González, J., Salvador, I., Ney, H., Vidal, E., Casacuberta, F.: Integrated handwriting recognition and interpretation using finite-state models. International Journal of Pattern Recognition and Artificial Intelligence 18(4), 519–539 (2004)Rabiner, L., Juang, B.H.: Fundamentals of speech recognition. Prentice-Hall, Englewood Cliffs (1993)Giménez, A., Juan, A.: Embedded bernoulli mixture hmms for handwritten word recognition. In: Proceedings of the 10th International Conference on Document Analysis and Recognition, Barcelona, Spain, pp. 896–900. IEEE Computer Society (July 2009)Toselli, A., Juan, A., Vidal, E.: Spontaneous handwriting recognition and classification. In: Proceedings of the International Conference on Pattern Recognition (ICPR 2004), Cambridge, United Kingdom, vol. 1, pp. 433–436 (August 2004)Marti, U.V., Bunke, H.: The IAM-database: an English sentence database for off-line handwriting recognition. International Journal on Document Analysis and Recognition (IJDAR) 5(1), 39–46 (2002)Romero, V., Toselli, A.H., Rodríguez, L., Vidal, E.: Computer Assisted Transcription for Ancient Text Images. In: Kamel, M.S., Campilho, A. (eds.) ICIAR 2007. LNCS, vol. 4633, pp. 1182–1193. Springer, Heidelberg (2007)Pérez, D., Tarazón, L., Serrano, N., Castro, F.M., Ramos-Terrades, O., Juan, A.: The germana database. In: Proceedings of the 10th International Conference on Document Analysis and Recognition, Barcelona, Spain, pp. 301–305. IEEE Computer Society (July 2009)Serrano, N., Juan, A.: The rodrigo database. In: Proceedings of the The Seventh International Conference on Language Resources and Evaluation (LREC 2010), Malta, May 19-21 (2010)Pechwitz, M., Maddouri, S.S., Magn̈er, V., Ellouze, N., Amiri, H.: IFN/ENIT-database of handwritten Arabic words. In: Proc. of the Colloque International Francophone sur l’Ecrit et le Document (CIFED), Hammmamet, Tunisia (October 2002