76 research outputs found

    Historical Handwritten Text Images Word Spotting through Sliding Window HOG Features

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    In this paper we present an innovative technique to semi-automatically index handwritten word images. The proposed method is based on HOG descriptors and exploits Dynamic Time Warping technique to compare feature vectors elaborated from single handwritten words. Our strategy is applied to a new challenging dataset extracted from Italian civil registries of the XIX century. Experimental results, compared with some previously developed word spotting strategies, confirmed that our method outperforms competitors

    On the modification of binarization algorithms to retain grayscale information for handwritten text recognition

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-19390-8_24[EN] The amount of digitized legacy documents has been rising over the last years due mainly to the increasing number of on-line digital libraries publishing this kind of documents. The vast majority of them remain waiting to be transcribed to provide historians and other researchers new ways of indexing, consulting and querying them. However, the performance accuracy of state-of-the-art Handwritten Text Recognition techniques decreases dramatically when they are applied to these historical documents. This is mainly due to the typical paper degradation problems. Therefore, robust pre-processing techniques is an important step for helping further recognition steps. This paper proposes to take existing binarization techniques, in order to retain their advantages, and modify them in such a way that some of the original grayscale information is preserved and be considered by the subsequent recognizer. Results are reported with the publicly available ESPOSALLES database.The research leading to these results has received funding from the European Union’s Seventh Framework Programme FP7/2007-2013) under grant agreement No. 600707 - tranScriptorium and the Spanish MEC under the STraDA project (TIN2012-37475-C02-01).Villegas, M.; Romero Gómez, V.; Sánchez Peiró, JA. (2015). On the modification of binarization algorithms to retain grayscale information for handwritten text recognition. En Pattern Recognition and Image Analysis: 7th Iberian Conference, IbPRIA 2015, Santiago de Compostela, Spain, June 17-19, 2015, Proceedings. Springer International Publishing. 208-215. https://doi.org/10.1007/978-3-319-19390-8_24S208215Drida, F.: Towards restoring historic documents degraded over time. In: Proceedings of 2nd IEEE International Conference on Document Image Analysis for Libraries (DIAL 2006), Lyon, France, pp. 350–357 (2006)Graves, A., Liwicki, M., Fernandez, S., Bertolami, R., Bunke, H., Schmidhuber, J.: A novel connectionist system for unconstrained handwriting recognition. IEEE Trans. Pattern Anal. Mach. Intell. 31(5), 855–868 (2009)Jelinek, F.: Statistical Methods for Speech Recognition. MIT Press, Cambridge (1998)Khurshid, K., Siddiqi, I., Faure, C., Vincent, N.: Comparison of niblack inspired binarization methods for ancient documents. In: Berkner, K., Likforman-Sulem, L. (eds.) 16th Document Recognition and Retrieval Conference, DRR 2009, SPIE Proceedings, vol. 7247, pp. 1–10. SPIE, San Jose (18–22 January 2009). doi: 10.1117/12.805827Kneser, R., Ney, H.: Improved backing-off for m-gram language modeling, Detroit, USA, vol. 1, pp. 181–184 (1995)Marti, U., Bunke, H.: Using a statistical language model to improve the preformance of an HMM-based cursive handwriting recognition system. IJPRAI 15(1), 65–90 (2001)Niblack, W.: An Introduction to Digital Image Processing, pp. 115–116. Prentice-Hall, Englewood Cliffs (1986)Romero, V., Fornés, A., Serrano, N., Sánchez, J., Toselli, A., Frinken, V., Vidal, E., Lladós, J.: The ESPOSALLES database: An ancient marriage license corpus for off-line handwriting recognition. Pattern Recogn. 46, 1658–1669 (2013). doi: 10.1016/j.patcog.2012.11.024España-Boquera, S., Castro-Bleda, M.J., Gorbe-Moya, J., Zamora-Martínez, F.: Improving offline handwriting text recognition with hybrid hmm/ann models. IEEE Trans. Pattern Anal. Mach. Intell. 33(4), 767–779 (2011)Sauvola, J., Pietikäinen, M.: Adaptive document image binarization. Pattern Recog. 33(2), 225–236 (2000). doi: 10.1016/S0031-3203(99)00055-2Shafait, F., Keysers, D., Breuel, T.M.: Efficient implementation of local adaptive thresholding techniques using integral images. In: Proceedings of the SPIE 6815, Document Recognition and Retrieval XV, 681510, pp. 1–6, January 2008. doi: 10.1117/12.767755Toselli, 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. Int. J. Pattern Recog. Artif. Intell. 18(4), 519–539 (2004). doi: 10.1142/S021800140400334

    A Generalization of Otsu's Method and Minimum Error Thresholding

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    We present Generalized Histogram Thresholding (GHT), a simple, fast, and effective technique for histogram-based image thresholding. GHT works by performing approximate maximum a posteriori estimation of a mixture of Gaussians with appropriate priors. We demonstrate that GHT subsumes three classic thresholding techniques as special cases: Otsu's method, Minimum Error Thresholding (MET), and weighted percentile thresholding. GHT thereby enables the continuous interpolation between those three algorithms, which allows thresholding accuracy to be improved significantly. GHT also provides a clarifying interpretation of the common practice of coarsening a histogram's bin width during thresholding. We show that GHT outperforms or matches the performance of all algorithms on a recent challenge for handwritten document image binarization (including deep neural networks trained to produce per-pixel binarizations), and can be implemented in a dozen lines of code or as a trivial modification to Otsu's method or MET.Comment: ECCV 202

    Complex Estimation of Strength Properties of Functional Materials on the Basis of the Analysis of Grain-Phase Structure Parameters

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    The technique allows analysis using grain-phase structure of the functional material to evaluate its performance, particularly strength properties. The technique is based on the use of linguistic variable in the process of comprehensive evaluation. An example of estimating the strength properties of steel reinforcement, subject to special heat treatment to obtain the desired grain-phase structure

    Interpretation, Evaluation and the Semantic Gap ... What if we Were on a Side-Track?

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    International audienceA significant amount of research in Document Image Analysis, and Machine Perception in general, relies on the extraction and analysis of signal cues with the goal of interpreting them into higher level information. This paper gives an overview on how this interpretation process is usually considered, and how the research communities proceed in evaluating existing approaches and methods developed for realizing these processes. Evaluation being an essential part to measuring the quality of research and assessing the progress of the state-of-the art, our work aims at showing that classical evaluation methods are not necessarily well suited for interpretation problems, or, at least, that they introduce a strong bias, not necessarily visible at first sight, and that new ways of comparing methods and measuring performance are necessary. It also shows that the infamous {\em Semantic Gap} seems to be an inherent and unavoidable part of the general interpretation process, especially when considered within the framework of traditional evaluation. The use of Formal Concept Analysis is put forward to leverage these limitations into a new tool to the analysis and comparison of interpretation contexts

    Previsual symptoms of Xylella fastidiosa infection revealed in spectral plant-trait alterations

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    Plant pathogens cause significant losses to agricultural yields, and increasingly threaten food security, ecosystem integrity, and societies in general. Xylella fastidiosa (Xf) is one of the most dangerous plant bacteria worldwide, causing several diseases with profound impacts on agriculture and the environment. Primarily occurring in the Americas, its recent discovery in Asia and Europe demonstrates a dramatically broadened geographic range. The Xf pathogen has thus re-emerged as a global threat, with its poorly contained expansion in Europe creating a socio-economic, cultural, and political disaster. Xf represents a threat of global proportion because it can infect over 350 plant species worldwide, and the early detection of Xf has been identified as a critical need for its eradication. Here, we show that changes in plant functional traits retrieved from airborne imaging spectroscopy and thermography reveal Xf infection in trees before symptoms are visible. We obtained accuracies of disease detection exceeding 80% when high-resolution solar-induced fluorescence quantified by 3D simulations and thermal-based stress indicators were coupled with photosynthetic traits sensitive to rapid pigment dynamics and degradation. Moreover, we found that the visually asymptomatic trees originally scored as affected via spectral plant trait alterations (presumed false positives) developed Xf symptoms four months later at almost double the rate of the asymptomatic trees classified as not affected by remote sensing. We demonstrate that spectral plant trait alterations caused by Xf infection are detectable at the landscape scale before symptoms are visible, a critical requirement to help eradicate some of the most devastating plant diseases worldwide.JRC.D.1-Bio-econom

    The association between single-parent family background and physical morbidity, mortality, and criminal behaviour in adulthood

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    Abstract The proportion of single-parent families has increased in the last few decades world-wide, mostly due to high divorce rates. Also in Finland growing numbers of children spend part of their childhood in single-parent families. The aim of this study was to investigate in a longitudinal perspective, the possible long-term effects of the childhood family structure on psychological, physical and criminal outcomes of an offspring during adulthood. A large, prospectively collected general population birth cohort (n= 11 017), the Northern Finland 1966 Birth Cohort, was used as a study population. This database provided the information on childhood family structure of cohort members with additional information of sociodemographic factors of the family and of the child. Information concerning physical and psychiatric illnesses were gathered from the Finnish Hospital Discharge Register (FHDR). Death certificates and the information from national crime registers were also obtained. Females with a single-parent family background were more commonly hospital-treated (61.3 % vs. 56.7 %) for any physical condition than females with a two-parent family background. For males such difference in overall physical illness was not found. Both females and males from single-parent families had more commonly been hospital-treated for some diagnoses in the ICD-category of "injury and poisoning" than had other cohort members. Furthermore, females from single-parent families had also more commonly been treated due to pregnancy-related conditions such as induced abortions. During the follow-up time (16 to 28 years of age) 117 (90 males, 27 females) cohort members had died. Males with single-parent family background exhibited an increased mortality risk, especially due to suicides (OR=2.5, 95% CI 1.1-5.8, adjusted for psychiatric hospital diagnosis, parental social class). Criminality was more common among both males and females from single-parent families compared with other cohort members. The results showed that the risk of violent offending and recidivism was increased up to 8-fold if the cohort male member had been born and raised in a single-mother family over most of his childhood. Parental divorce also doubled the risk for both violent and recidivistic offending. Non-violent offences among males were associated only with parental death and divorce. Furthermore, drunk driving was more common among both males and females with single-parent background. Males who were born into single-mother families were at the highest risk of drunk driving offences in adulthood (OR=2.4, 95% CI 1.4-4.2, adjusted for maternal age, psychiatric hospital diagnosis, parental social class). In this study it was shown that young adults with single-parent families in childhood experienced a more stressful pathway from late adolescence to adulthood. However, most of the offspring of single-parent families did well during the follow-up time. Strategies to promote the well-being of children and adolescents in single-parent families are of prime importance for preventive health care
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