An iterative multimodal framework for the transcription of handwritten historical documents

[EN] The transcription of historical documents is one of the most interesting tasks in which Handwritten Text Recognition can be applied, due to its interest in humanities research.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 An iterative multimodal framework for the transcription of handwritten historical documents.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

Using word graphs as intermediate representation of uttered sentences

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-33275-3_35We present an algorithm for building graphs of words as an intermediate representation of uttered sentences. No language model is used. The input data for the algorithm are the pronunciation lexicon organized as a tree and the sequence of acoustic frames. The transition between consecutive units are considered as additional units. Nodes represent discrete instants of time, arcs are labelled with words, and a confidence measure is assigned to each detected word, which is computed by using the phonetic probabilities of the subsequence of acoustic frames used for completing the word. We evaluated the obtained word graphs by searching the path that best matches with the correct sentence and then measuring the word accuracy, i.e. the oracle word accuracy. © 2012 Springer-Verlag.This work was supported by the Spanish MICINN under contract TIN2011-28169-C05-01 and the Vic. d’Investigació of the UPV under contract 20110897.Gómez Adrian, JA.; Sanchís Arnal, E. (2012). Using word graphs as intermediate representation of uttered sentences. En Progress in Pattern Recognition, Image Analysis, Computer Vision, and Applications. Springer Verlag (Germany). 284-291. doi:10.1007/978-3-642-33275-3_35S284291Ortmanns, S., Ney, H., Aubert, X.: A word graph algorithm for large vocabulary continuous speech recognition. Computer Speech and Language 11, 43–72 (1997)Ney, H., Ortmanns, S., Lindam, I.: Extensions to the word graph method for large vocabulary continuous speech recognition. In: Proceedings of IEEE ICASSP 1997, Munich, Germany, vol. 3, pp. 1791–1794 (1997)Wessel, F., Schlüter, R., Macherey, K., Ney, H.: Confidence Measures for Large Vocabulary Continuous Speech Recognition. IEEE Transactions on Speech and Audio Processing 9(3), 288–298 (2001)Ferreiros, J., San-Segundo, R., Fernández, F., D’Haro, L.-F., Sama, V., Barra, R., Mellén, P.: New word-level and sentence-level confidence scoring using graph theory calculus and its evaluation on speech understanding. In: Proceedings of INTERSPEECH 2005, Lisbon, Portugal, pp. 3377–3380 (2005)Raymond, C., Béchet, F., De Mori, R., Damnati, G.: On the use of finite state transducers for semantic interpretation. Speech Communication 48, 288–304 (2006)Hakkani-Tür, D., Béchet, F., Riccardi, G., Tur, G.: Beyond ASR 1-best: Using word confusion networks in spoken language understanding. Computer Speech and Language 20, 495–514 (2006)Justo, R., Pérez, A., Torres, M.I.: Impact of the Approaches Involved on Word-Graph Derivation from the ASR System. In: Vitrià, J., Sanches, J.M., Hernández, M. (eds.) IbPRIA 2011. LNCS, vol. 6669, pp. 668–675. Springer, Heidelberg (2011)Gómez, J.A., Calvo, M.: Improvements on Automatic Speech Segmentation at the Phonetic Level. In: San Martin, C., Kim, S.-W. (eds.) CIARP 2011. LNCS, vol. 7042, pp. 557–564. Springer, Heidelberg (2011)Calvo, M., Gómez, J.A., Sanchis, E., Hurtado, L.F.: An algorithm for automatic speech understanding over word graphs. Procesamiento del Lenguaje Natural (48) (accepted, pending of publication, 2012)Moreno, A., Poch, D., Bonafonte, A., Lleida, E., Llisterri, J., Mariño, J.B., Nadeu, C.: Albayzin Speech Database: Design of the Phonetic Corpus. In: Proceedings of Eurospeech, Berlin, Germany, vol. 1, pp. 653–656 (September 1993)Benedí, J.M., Lleida, E., Varona, A., Castro, M., Galiano, I., Justo, R., López, I., Miguel, A.: Design and acquisition of a telephone spontaneous speech dialogue corpus in Spanish: DIHANA. In: Proc. of LREC 2006, Genova, Italy (2006

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

Discriminative estimation of probabilistic context-free grammars for mathematical expression recognition and retrieval

[EN] We present a discriminative learning algorithm for the probabilistic estimation of two-dimensional probabilistic context-free grammars (2D-PCFG) for mathematical expressions recognition and retrieval. This algorithm is based on a generalization of the H-criterion as the objective function and the growth transformations as the optimization method. For the development of the discriminative estimation algorithm, the N-best interpretations provided by the 2D-PCFG have been considered. Experimental results are reported on two available datasets: Im2Latex and IBEM. The first experiment compares the proposed discriminative estimation method with the classic Viterbi-based estimation method. The second one studies the performance of the estimated models depending on the length of the mathematical expressions and the number of admissible errors in the metric used.This research has been developed with the support of Grant PID2020-116813RBI00a funded by MCIN/AEI/ 10.13039/501100011033 and FPI grant CIACIF/2021/313 funded by Generalitat Valenciana. Universitat Politecnica de Valencia Grant No. SP20210263Noya García, E.; Benedí Ruiz, JM.; Sánchez Peiró, JA.; Anitei, D. (2023). Discriminative estimation of probabilistic context-free grammars for mathematical expression recognition and retrieval. Pattern Analysis and Applications. 26:1571-1584. https://doi.org/10.1007/s10044-023-01158-81571158426Bahl LR, Jelinek F, Mercer RL (1983) A maximum likelihood approach to continuous speech recognition. IEEE Trans Pattern Anal Machine Intell 5(2):179–190Koehn P (2009) Statistical Machine Translation. Cambridge University Press, ???. https://doi.org/10.1017/CBO9780511815829Graves A, Fernández S, Gomez F, Schmidhuber J (2006) Connectionist temporal classification: Labelling unsegmented sequence data with recurrent neural networks. In: ICML, vol 2006, pp 369–376. https://doi.org/10.1145/1143844.1143891Marzal A (1993) Cálculo de las k mejores soluciones a problemas de programación dinámica. PhD thesis, Universidad Politécnica de ValenciaJiménez VM, Marzal A (2000) Computation of the N Best Parse Trees for Weighted and Stochastic Context-Free Grammars. In: Advances in Pattern Recognition. Lecture Notes in Computer Science, 1876, pp 183–192 https://doi.org/10.1007/3-540-44522-6_19Ortmanns S, Ney H, Aubert X (1997) A word graph algorithm for large vocabulary continuous speech recognition. Comput Speech Lang 11(1):43–72. https://doi.org/10.1006/csla.1996.0022Noya E, Sánchez JA, Benedí JM (2021) Generation of Hypergraphs from the N-Best Parsing of 2D-Probabilistic Context-Free Grammars for Mathematical Expression Recognition. In: ICPR, pp 5696–5703. https://doi.org/10.1109/ICPR48806.2021.9412273Ueffing N, Och FJ, Ney H (2002) Generation of word graphs in statistical machine translation. In: Proceedings of the 2002 conference on empirical methods in natural language processing (EMNLP 2002), pp 156–163. Association for Computational Linguistics, ???. https://doi.org/10.3115/1118693.1118714. https://aclanthology.org/W02-1021Toselli AH, Vidal E, Puigcerver J, Noya-García E (2019) Probabilistic multi-word spotting in handwritten text images. Pattern Anal Appl 22:23–32. https://doi.org/10.1007/s10044-018-0742-zSánchez-Sáez R, Sánchez JA, Benedí JM (2010) Confidence measures for error discrimination in an interactive predictive parsing framework. In: Coling, pp 1220–1228Benedí JM, Sánchez JA (2005) Estimation of stochastic context-free grammars and their use as language models. Comput Speech Lang 19(3):249–274. https://doi.org/10.1016/j.csl.2004.09.001Awal AM, Mouchère H, Viard-Gaudin C (2012) A global learning approach for an online handwritten mathematical expression recognition system. Pattern Recogn Lett 35:68–77. https://doi.org/10.1016/j.patrec.2012.10.024Álvaro F, Sánchez JA, Benedí JM (2016) An Integrated Grammar-based Approach for Mathematical Expression Recognition. Pattern Recogn 51:135–147. https://doi.org/10.1016/j.patcog.2015.09.013Deng Y, Kanervisto A, Ling J, Rush AM (2017) Image-to-markup generation with coarse-to-fine attention. In: Proceedings of the ICML-17, pp 980–989Anitei D, Sánchez JA, Fuentes JM, Paredes R, Benedí JM (2021) ICDAR2021 Competition on mathematical formula detection. In: ICDAR, pp 783–795. https://doi.org/10.1007/978-3-030-86337-1_52Gopalakrishnan PS, Kanevsky D, Nadas A, Nahamoo D (1991) An inequality for rational functions with applications to some statistical estimation problems. IEEE Trans Inf Theory 37(1):107–113. https://doi.org/10.1109/18.61108Maca M, Benedí JM, Sánchez JA (2021) Discriminative Learning for Probabilistic Context-Free Grammars based on Generalized H-Criterion. Preprint arXiv:2103.08656arXiv:2103.08656 [cs.CL]Woodland PC, Povey D (2002) Large scale discriminative training of hidden Markov models for speech recognition. Comput Speech Lang 16(1):25–47. https://doi.org/10.1006/csla.2001.0182Noya E, Benedí JM, Sánchez JA, Anitei D (2022) Discriminative learning of two-dimensional probabilistic context-free grammars for mathematical expression recognition and retrieval. In: IbPRIA, pp 333–347. https://doi.org/10.1007/978-3-031-04881-4_27Zanibbi R, Blostein D (2011) Recognition and Retrieval of Mathematical Expressions. IJDAR 15:331–357. https://doi.org/10.1007/s10032-011-0174-4Huang J, Tan J, Bi N (2020) Overview of mathematical expression recognition. In: Pattern recognition and artificial intelligence, pp 41–54. https://doi.org/10.1007/978-3-030-59830-3_4Mahdavi M, Zanibbi R, Mouchere H, Viard-Gaudin C, Garain U (2019) ICDAR 2019 CROHME + TFD: Competition on recognition of handwritten mathematical expressions and typeset formula detection. In: ICDAR, pp 1533–1538. https://doi.org/10.1109/ICDAR.2019.00247Wang DH, Yin F, Wu JW, Yan YP, Huang ZC, Chen GY, Wang Y, Liu CL (2020) ICFHR 2020 Competition on offline recognition and spotting of handwritten mathematical expressions - OffRaSHME. In: ICFHR, pp. 211–215. https://doi.org/10.1109/ICFHR2020.2020.00047Wan Z, Fan K, Wang Q, Zhang S (2019) Recognition of printed mathematical formula symbols based on convolutional neural network. DEStech Transactions on Computer Science and Engineering. https://doi.org/10.12783/dtcse/ica2019/30711Wu J-W, Yin F, Zhang Y-M, Zhang X-Y, Liu C-L (2020) Handwritten mathematical expression recognition via paired adversarial learning. Int J Comput Vis 128:2386–401. https://doi.org/10.1007/s11263-020-01291-5Peng S, Gao L, Yuan K, Tang Z (2021) Image to LaTeX with Graph Neural Network for Mathematical Formula Recognition. In: ICDAR, pp 648–663. https://doi.org/10.1007/978-3-030-86331-9_42Zhao W, Gao L, Yan Z, Peng S, Du L, Zhang Z (2021) Handwritten mathematical expression recognition with bidirectionally trained transformer. In: Document analysis and recognition – ICDAR 2021, pp 570–584. https://doi.org/10.1007/978-3-030-86331-9_37Davila K, Joshi R, Setlur S, Govindaraju V, Zanibbi R (2019) Tangent-V: Math formula image search using line-of-sight graphs, pp 681–695. https://doi.org/10.1007/978-3-030-15712-8_44Zhong W, Zanibbi R (2019) Structural similarity search for formulas using leaf-root paths in operator subtrees, pp 116–129. https://doi.org/10.1007/978-3-030-15712-8_8Mansouri B, Zanibbi R, Oard D (2019) Characterizing searches for mathematical concepts, pp 57–66. https://doi.org/10.1109/JCDL.2019.00019Chou PA (1989) Recognition of equations using a two-dimensional stochastic context-free grammar. In: Visual communications and image processing IV, vol 1199, pp 852–863. https://doi.org/10.1117/12.970095Pr$$\mathring{u}$$ša D, Hlaváč V (2007) Mathematical Formulae Recognition Using 2D Grammars. ICDAR 2, 849–853. https://doi.org/10.1109/ICDAR.2007.4377035Lari K, Young SJ (1991) Applications of stochastic context-free grammars using the inside-outside algorithm. Comput Speech Lang 5(3):237–257. https://doi.org/10.1016/0885-2308(91)90009-FNey H (1992) Stochastic grammars and pattern recognition. In: Laface, P., De Mori, R. (eds.) Speech recognition and understanding, pp 319–344. https://doi.org/10.1007/978-3-642-76626-8_34Baum LE, Sell GR (1968) Growth transformation for functions on manifolds. Pac J Math 27(2):211–227Casacuberta F (1996) Growth transformations for probabilistic functions of stochastic grammars. IJPRAI 10(3):183–201. https://doi.org/10.1142/S0218001496000153Gopalakrishnan P, Kanevsky D, Nadas A, Nahamoo D, Picheny M (1988) Decoder selection based on cross-entropies. In: ICASSP-88, vol 1, pp 20–23. https://doi.org/10.1109/ICASSP.1988.196499Papineni K, Roukos S, Ward T, Zhu WJ (2002) BLEU: a method for automatic evaluation of machine translation. In: ACL, pp 311–318. https://doi.org/10.3115/1073083.1073135Suzuki M, Tamari F, Fukuda R, Uchida S, Kanahori T (2003) Infty: an integrated ocr system for mathematical documents, pp 95–104. https://doi.org/10.1145/958220.958239Shi B, Bai X, Yao C (2017) An end-to-end trainable neural network for image-based sequence recognition and its application to scene text recognition. TPAMI 39–11:2298–2304. https://doi.org/10.1109/TPAMI.2016.2646371Singh S (2018) Teaching machines to code: neural markup generation with visual attention. Preprint arXiv:1802.05415arXiv:1802.05415 [cs.CL

Computation of moments for probabilistic finite-state automata

[EN] The computation of moments of probabilistic finite-state automata (PFA) is researched in this article. First, the computation of moments of the length of the paths is introduced for general PFA, and then, the computation of moments of the number of times that a symbol appears in the strings generated by the PFA is described. These computations require a matrix inversion. Acyclic PFA, such as word graphs, are quite common in many practical applications. Algorithms for the efficient computation of the moments for acyclic PFA are also presented in this paper.This work has been partially supported by the Ministerio de Ciencia y Tecnologia under the grant TIN2017-91452-EXP (IBEM), by the Generalitat Valenciana under the grant PROMETE0/2019/121 (DeepPattern), and by the grant "Ayudas Fundacion BBVA a equipos de investigacion cientifica 2018" (PR[8]_HUM_C2_0087).Sánchez Peiró, JA.; Romero, V. (2020). Computation of moments for probabilistic finite-state automata. Information Sciences. 516:388-400. https://doi.org/10.1016/j.ins.2019.12.052S388400516Sakakibara, Y., Brown, M., Hughey, R., Mian, I. S., Sjölander, K., Underwood, R. C., & Haussler, D. (1994). Stochastic context-free grammers for tRNA modeling. Nucleic Acids Research, 22(23), 5112-5120. doi:10.1093/nar/22.23.5112Álvaro, F., Sánchez, J.-A., & Benedí, J.-M. (2016). An integrated grammar-based approach for mathematical expression recognition. Pattern Recognition, 51, 135-147. doi:10.1016/j.patcog.2015.09.013Mohri, M., Pereira, F., & Riley, M. (2002). Weighted finite-state transducers in speech recognition. Computer Speech & Language, 16(1), 69-88. doi:10.1006/csla.2001.0184Casacuberta, F., & Vidal, E. (2004). Machine Translation with Inferred Stochastic Finite-State Transducers. Computational Linguistics, 30(2), 205-225. doi:10.1162/089120104323093294Ortmanns, S., Ney, H., & Aubert, X. (1997). A word graph algorithm for large vocabulary continuous speech recognition. Computer Speech & Language, 11(1), 43-72. doi:10.1006/csla.1996.0022Soule, S. (1974). Entropies of probabilistic grammars. Information and Control, 25(1), 57-74. doi:10.1016/s0019-9958(74)90799-2Justesen, J., & Larsen, K. J. (1975). On probabilistic context-free grammars that achieve capacity. Information and Control, 29(3), 268-285. doi:10.1016/s0019-9958(75)90437-4Hernando, D., Crespi, V., & Cybenko, G. (2005). Efficient Computation of the Hidden Markov Model Entropy for a Given Observation Sequence. IEEE Transactions on Information Theory, 51(7), 2681-2685. doi:10.1109/tit.2005.850223Nederhof, M.-J., & Satta, G. (2008). Computation of distances for regular and context-free probabilistic languages. Theoretical Computer Science, 395(2-3), 235-254. doi:10.1016/j.tcs.2008.01.010CORTES, C., MOHRI, M., RASTOGI, A., & RILEY, M. (2008). ON THE COMPUTATION OF THE RELATIVE ENTROPY OF PROBABILISTIC AUTOMATA. International Journal of Foundations of Computer Science, 19(01), 219-242. doi:10.1142/s0129054108005644Ilic, V. M., Stankovi, M. S., & Todorovic, B. T. (2011). Entropy Message Passing. IEEE Transactions on Information Theory, 57(1), 375-380. doi:10.1109/tit.2010.2090235Booth, T. L., & Thompson, R. A. (1973). Applying Probability Measures to Abstract Languages. IEEE Transactions on Computers, C-22(5), 442-450. doi:10.1109/t-c.1973.223746Thompson, R. A. (1974). Determination of Probabilistic Grammars for Functionally Specified Probability-Measure Languages. IEEE Transactions on Computers, C-23(6), 603-614. doi:10.1109/t-c.1974.224001Wetherell, C. S. (1980). Probabilistic Languages: A Review and Some Open Questions. ACM Computing Surveys, 12(4), 361-379. doi:10.1145/356827.356829Sanchez, J.-A., & Benedi, J.-M. (1997). Consistency of stochastic context-free grammars from probabilistic estimation based on growth transformations. IEEE Transactions on Pattern Analysis and Machine Intelligence, 19(9), 1052-1055. doi:10.1109/34.615455Hutchins, S. E. (1972). Moments of string and derivation lengths of stochastic context-free grammars. Information Sciences, 4(2), 179-191. doi:10.1016/0020-0255(72)90011-4Heim, A., Sidorenko, V., & Sorger, U. (2008). Computation of distributions and their moments in the trellis. Advances in Mathematics of Communications, 2(4), 373-391. doi:10.3934/amc.2008.2.373Vidal, E., Thollard, F., de la Higuera, C., Casacuberta, F., & Carrasco, R. C. (2005). Probabilistic finite-state machines - part I. IEEE Transactions on Pattern Analysis and Machine Intelligence, 27(7), 1013-1025. doi:10.1109/tpami.2005.147Sánchez, J. A., Rocha, M. A., Romero, V., & Villegas, M. (2018). On the Derivational Entropy of Left-to-Right Probabilistic Finite-State Automata and Hidden Markov Models. Computational Linguistics, 44(1), 17-37. doi:10.1162/coli_a_0030

The TransLectures-UPV Toolkit

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-13623-3_28Over the past few years, online multimedia educational repositories have increased in number and popularity. The main aim of the transLectures project is to develop cost-effective solutions for producing accurate transcriptions and translations for large video lecture repositories, such as VideoLectures.NET or the Universitat Politècnica de València s repository, poliMedia. In this paper, we present the transLectures-UPV toolkit (TLK), which has been specifically designed to meet the requirements of the transLectures project, but can also be used as a conventional ASR toolkit. The main features of the current release include HMM training and decoding with speaker adaptation techniques (fCMLLR). TLK has been tested on the VideoLectures.NET and poliMedia repositories, yielding very competitive results. TLK has been released under the permissive open source Apache License v2.0 and can be directly downloaded from the transLectures website.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 287755 (transLectures) and ICT Policy Support Programme (ICT PSP/2007-2013) as part of the Competitiveness and InnovationFramework Programme (CIP) under grant agreement no 621030 (EMMA), andthe Spanish MINECO Active2Trans (TIN2012-31723) research project.Del Agua Teba, MA.; Giménez Pastor, A.; Serrano Martinez Santos, N.; Andrés Ferrer, J.; Civera Saiz, J.; Sanchis Navarro, JA.; Juan Císcar, A. (2014). The TransLectures-UPV Toolkit. En Advances in Speech and Language Technologies for Iberian Languages: Second International Conference, IberSPEECH 2014, Las Palmas de Gran Canaria, Spain, November 19-21, 2014. Proceedings. Springer International Publishing. 269-278. https://doi.org/10.1007/978-3-319-13623-3_28S269278Final report on massive adaptation (M36). To be delivered on October 2014 (2014)First report on massive adaptation (M12), https://www.translectures.eu/wp-content/uploads/2013/05/transLectures-D3.1.1-18Nov2012.pdfOpencast Matterhorn, http://opencast.org/matterhorn/sclite - Score speech recognition system output, http://www1.icsi.berkeley.edu/Speech/docs/sctk-1.2/sclite.htmSecond report on massive adaptation (M24), https://www.translectures.eu//wp-content/uploads/2014/01/transLectures-D3.1.2-15Nov2013.pdfTLK: The transLectures-UPV Toolkit, https://www.translectures.eu/tlk/Baum, L.E., Petrie, T., Soules, G., Weiss, N.: A Maximization Technique Occurring in the Statistical Analysis of Probabilistic Functions of Markov Chains. The Annals of Mathematical Statistics 41(1), 164–171 (1970)Dahl, G.E., Yu, D., Deng, L., Acero, A.: Context-Dependent Pre-Trained Deep Neural Networks for Large-Vocabulary Speech Recognition. IEEE Transactions on Audio, Speech, and Language Processing 20(1), 30–42 (2012)Digalakis, V., Rtischev, D., Neumeyer, L., Sa, E.: Speaker Adaptation Using Constrained Estimation of Gaussian Mixtures. IEEE Transactions on Speech and Audio Processing 3, 357–366 (1995)Huang, J.T., Li, J., Yu, D., Deng, L., Gong, Y.: Cross-language knowledge transfer using multilingual deep neural network with shared hidden layers. In: Proc. of ICASSP (2013)Munteanu, C., Baecker, R., Penn, G., Toms, E., James, D.: The Effect of Speech Recognition Accuracy Rates on the Usefulness and Usability of Webcast Archives. In: Proc. of CHI, pp. 493–502 (2006)Ney, H., Ortmanns, S.: Progress in dynamic programming search for LVCSR. Proceedings of the IEEE 88(8), 1224–1240 (2000)Ortmanns, S., Ney, H., Eiden, A.: Language-model look-ahead for large vocabulary speech recognition. In: Proc. of ICSLP, vol. 4, pp. 2095–2098 (1996)Ortmanns, S., Ney, H., Aubert, X.: A word graph algorithm for large vocabulary continuous speech recognition. Computer Speech and Language 11(1), 43–72 (1997)Povey, D., et al.: The Kaldi Speech Recognition Toolkit. In: Proc. of ASRU (2011)Rumelhart, D., Hintont, G., Williams, R.: Learning representations by back-propagating errors. Nature 323(6088), 533–536 (1986)Rybach, D., et al.: The RWTH Aachen University Open Source Speech Recognition System. In: Proc. Interspeech, pp. 2111–2114 (2009)Seide, F., Li, G., Chen, X., Yu, D.: Feature engineering in Context-Dependent Deep Neural Networks for conversational speech transcription. In: Proc. of ASRU, pp. 24–29 (2011)Viterbi, A.: Error bounds for convolutional codes and an asymptotically optimum decoding algorithm. IEEE Transactions on Information Theory 13(2), 260–269 (1967)Young, S., et al.: The HTK Book. Cambridge University Engineering Department (1995)Young, S.J., Odell, J.J., Woodland, P.C.: Tree-based state tying for high accuracy acoustic modelling. In: Proc. of HLT, pp. 307–312 (1994

CONTRIBUTIONS TO EFFICIENT AUTOMATIC TRANSCRIPTION OF VIDEO LECTURES

Tesis por compendio[ES] Durante los últimos años, los repositorios multimedia en línea se han convertido en fuentes clave de conocimiento gracias al auge de Internet, especialmente en el área de la educación. Instituciones educativas de todo el mundo han dedicado muchos recursos en la búsqueda de nuevos métodos de enseñanza, tanto para mejorar la asimilación de nuevos conocimientos, como para poder llegar a una audiencia más amplia. Como resultado, hoy en día disponemos de diferentes repositorios con clases grabadas que siven como herramientas complementarias en la enseñanza, o incluso pueden asentar una nueva base en la enseñanza a distancia. Sin embargo, deben cumplir con una serie de requisitos para que la experiencia sea totalmente satisfactoria y es aquí donde la transcripción de los materiales juega un papel fundamental. La transcripción posibilita una búsqueda precisa de los materiales en los que el alumno está interesado, se abre la puerta a la traducción automática, a funciones de recomendación, a la generación de resumenes de las charlas y además, el poder hacer llegar el contenido a personas con discapacidades auditivas. No obstante, la generación de estas transcripciones puede resultar muy costosa. Con todo esto en mente, la presente tesis tiene como objetivo proporcionar nuevas herramientas y técnicas que faciliten la transcripción de estos repositorios. En particular, abordamos el desarrollo de un conjunto de herramientas de reconocimiento de automático del habla, con énfasis en las técnicas de aprendizaje profundo que contribuyen a proporcionar transcripciones precisas en casos de estudio reales. Además, se presentan diferentes participaciones en competiciones internacionales donde se demuestra la competitividad del software comparada con otras soluciones. Por otra parte, en aras de mejorar los sistemas de reconocimiento, se propone una nueva técnica de adaptación de estos sistemas al interlocutor basada en el uso Medidas de Confianza. Esto además motivó el desarrollo de técnicas para la mejora en la estimación de este tipo de medidas por medio de Redes Neuronales Recurrentes. Todas las contribuciones presentadas se han probado en diferentes repositorios educativos. De hecho, el toolkit transLectures-UPV es parte de un conjunto de herramientas que sirve para generar transcripciones de clases en diferentes universidades e instituciones españolas y europeas.[CA] Durant els últims anys, els repositoris multimèdia en línia s'han convertit en fonts clau de coneixement gràcies a l'expansió d'Internet, especialment en l'àrea de l'educació. Institucions educatives de tot el món han dedicat molts recursos en la recerca de nous mètodes d'ensenyament, tant per millorar l'assimilació de nous coneixements, com per poder arribar a una audiència més àmplia. Com a resultat, avui dia disposem de diferents repositoris amb classes gravades que serveixen com a eines complementàries en l'ensenyament, o fins i tot poden assentar una nova base a l'ensenyament a distància. No obstant això, han de complir amb una sèrie de requisits perquè la experiència siga totalment satisfactòria i és ací on la transcripció dels materials juga un paper fonamental. La transcripció possibilita una recerca precisa dels materials en els quals l'alumne està interessat, s'obri la porta a la traducció automàtica, a funcions de recomanació, a la generació de resums de les xerrades i el poder fer arribar el contingut a persones amb discapacitats auditives. No obstant, la generació d'aquestes transcripcions pot resultar molt costosa. Amb això en ment, la present tesi té com a objectiu proporcionar noves eines i tècniques que faciliten la transcripció d'aquests repositoris. En particular, abordem el desenvolupament d'un conjunt d'eines de reconeixement automàtic de la parla, amb èmfasi en les tècniques d'aprenentatge profund que contribueixen a proporcionar transcripcions precises en casos d'estudi reals. A més, es presenten diferents participacions en competicions internacionals on es demostra la competitivitat del programari comparada amb altres solucions. D'altra banda, per tal de millorar els sistemes de reconeixement, es proposa una nova tècnica d'adaptació d'aquests sistemes a l'interlocutor basada en l'ús de Mesures de Confiança. A més, això va motivar el desenvolupament de tècniques per a la millora en l'estimació d'aquest tipus de mesures per mitjà de Xarxes Neuronals Recurrents. Totes les contribucions presentades s'han provat en diferents repositoris educatius. De fet, el toolkit transLectures-UPV és part d'un conjunt d'eines que serveix per generar transcripcions de classes en diferents universitats i institucions espanyoles i europees.[EN] During the last years, on-line multimedia repositories have become key knowledge assets thanks to the rise of Internet and especially in the area of education. Educational institutions around the world have devoted big efforts to explore different teaching methods, to improve the transmission of knowledge and to reach a wider audience. As a result, online video lecture repositories are now available and serve as complementary tools that can boost the learning experience to better assimilate new concepts. In order to guarantee the success of these repositories the transcription of each lecture plays a very important role because it constitutes the first step towards the availability of many other features. This transcription allows the searchability of learning materials, enables the translation into another languages, provides recommendation functions, gives the possibility to provide content summaries, guarantees the access to people with hearing disabilities, etc. However, the transcription of these videos is expensive in terms of time and human cost. To this purpose, this thesis aims at providing new tools and techniques that ease the transcription of these repositories. In particular, we address the development of a complete Automatic Speech Recognition Toolkit with an special focus on the Deep Learning techniques that contribute to provide accurate transcriptions in real-world scenarios. This toolkit is tested against many other in different international competitions showing comparable transcription quality. Moreover, a new technique to improve the recognition accuracy has been proposed which makes use of Confidence Measures, and constitutes the spark that motivated the proposal of new Confidence Measures techniques that helped to further improve the transcription quality. To this end, a new speaker-adapted confidence measure approach was proposed for models based on Recurrent Neural Networks. The contributions proposed herein have been tested in real-life scenarios in different educational repositories. In fact, the transLectures-UPV toolkit is part of a set of tools for providing video lecture transcriptions in many different Spanish and European universities and institutions.Agua Teba, MÁD. (2019). CONTRIBUTIONS TO EFFICIENT AUTOMATIC TRANSCRIPTION OF VIDEO LECTURES [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/130198TESISCompendi

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. 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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. 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