Automatic Document Image Binarization using Bayesian Optimization

Document image binarization is often a challenging task due to various forms of degradation. Although there exist several binarization techniques in literature, the binarized image is typically sensitive to control parameter settings of the employed technique. This paper presents an automatic document image binarization algorithm to segment the text from heavily degraded document images. The proposed technique uses a two band-pass filtering approach for background noise removal, and Bayesian optimization for automatic hyperparameter selection for optimal results. The effectiveness of the proposed binarization technique is empirically demonstrated on the Document Image Binarization Competition (DIBCO) and the Handwritten Document Image Binarization Competition (H-DIBCO) datasets

ICFHR2016 Handwritten Keyword Spotting Competition (H-KWS 2016)

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] The H-KWS 2016, organized in the context of the ICFHR 2016 conference aims at setting up an evaluation framework for benchmarking handwritten keyword spotting (KWS) examining both the Query by Example (QbE) and the Query by String (QbS) approaches. Both KWS approaches were hosted into two different tracks, which in turn were split into two distinct challenges, namely, a segmentation-based and a segmentation-free to accommodate different perspectives adopted by researchers in the KWS field. In addition, the competition aims to evaluate the submitted training-based methods under different amounts of training data. Four participants submitted at least one solution to one of the challenges, according to the capabilities and/or restrictions of their systems. The data used in the competition consisted of historical German and English documents with their own characteristics and complexities. This paper presents the details of the competition, including the data, evaluation metrics and results of the best run of each participating methods.This work was partially supported by the Spanish MEC under FPU grant FPU13/06281, by the Generalitat Valenciana under the Prometeo/2009/014 project grant ALMA-MATER, and through the EU projects: HIMANIS (JPICH programme, Spanish grant Ref. PCIN-2015-068) and READ (Horizon-2020 programme, grant Ref. 674943).Pratikakis, I.; Zagoris, K.; Gatos, B.; Puigcerver, J.; Toselli, AH.; Vidal, E. (2016). ICFHR2016 Handwritten Keyword Spotting Competition (H-KWS 2016). IEEE. https://doi.org/10.1109/ICFHR.2016.0117

Cranioplasty optimal timing in cases of decompressive craniectomy after severe head injury: a systematic literature review

AbstractObjectCranioplasty has been considered for several decades as a protective and cosmetic procedure. It has recently been postulated that cranioplasty may have a therapeutic role, and improve the patient’s functional outcome after decompressive craniectomy (DC). The appropriate timing for cranioplasty remains unknown. In our current study, we review the literature for evaluating the relationship of cranioplasty timing and its complication rate and outcome.MethodsThe PubMed database was searched to identify any relevant articles. The following terms were used as keywords: “cranioplasty”, “timing cranioplasty”, “early cranioplasty”, “late cranioplasty”, “delayed cranioplasty”, “early versus late cranioplasty”. Clinical studies with more than 10 participants, and closed head injury as the underlying cause for DC were included in our study. The study design, the timing performing cranioplasty, the complication rate, and the patients’ outcome were evaluated.ResultsTen clinical series met our inclusion criteria. The observed complication rate associated to cranioplasty after DC is not negligible. Several reports have demonstrated that late cranioplasty may minimize procedure-associated complications. Early cranioplasty has been associated with complications, but improves CSF dynamics, and regional cerebral perfusion and metabolism, minimizes the complications from a sunken scalp, reduces the overall length of hospitalization, and thus the overall cost of care.ConclusionsCranioplasty is a relatively simple procedure that is nevertheless burdened by considerable morbidity. However, an early cranioplasty procedure may improve the outcome in selected cases. Prospective, large-scale studies are necessary to outline the actual complication rate, the neurological outcome, and define the optimal timing for a cranioplasty

Digitisation Processing and Recognition of Old Greek Manuscipts (the D-SCRIBE Project)

After many years of scholar study, manuscript collections continue to be an important source of novel information for scholars, concerning both the history of earlier times as well as the development of cultural documentation over the centuries. D-SCRIBE project aims to support and facilitate current and future efforts in manuscript digitization and processing. It strives toward the creation of a comprehensive software product, which can assist the content holders in turning an archive of manuscripts into a digital collection using automated methods. In this paper, we focus on the problem of recognizing early Christian Greek manuscripts. We propose a novel digital image binarization scheme for low quality historical documents allowing further content exploitation in an efficient way. Based on the existence of closed cavity regions in the majority of characters and character ligatures in these scripts, we propose a novel, segmentation-free, fast and efficient technique that assists the recognition procedure by tracing and recognizing the most frequently appearing characters or character ligatures

Transforming scholarship in the archives through handwritten text recognition:Transkribus as a case study

Purpose: An overview of the current use of handwritten text recognition (HTR) on archival manuscript material, as provided by the EU H2020 funded Transkribus platform. It explains HTR, demonstrates Transkribus, gives examples of use cases, highlights the affect HTR may have on scholarship, and evidences this turning point of the advanced use of digitised heritage content. The paper aims to discuss these issues. - Design/methodology/approach: This paper adopts a case study approach, using the development and delivery of the one openly available HTR platform for manuscript material. - Findings: Transkribus has demonstrated that HTR is now a useable technology that can be employed in conjunction with mass digitisation to generate accurate transcripts of archival material. Use cases are demonstrated, and a cooperative model is suggested as a way to ensure sustainability and scaling of the platform. However, funding and resourcing issues are identified. - Research limitations/implications: The paper presents results from projects: further user studies could be undertaken involving interviews, surveys, etc. - Practical implications: Only HTR provided via Transkribus is covered: however, this is the only publicly available platform for HTR on individual collections of historical documents at time of writing and it represents the current state-of-the-art in this field. - Social implications: The increased access to information contained within historical texts has the potential to be transformational for both institutions and individuals. - Originality/value: This is the first published overview of how HTR is used by a wide archival studies community, reporting and showcasing current application of handwriting technology in the cultural heritage sector

Structure-Property Relationships in Rubber/Layered Silicate Nanocomposites

The scientific and industrial interest devoted to polymer/layered silicate nanocomposites due to their outstanding properties and novel applications resulted in numerous studies in the last decade. They cover mostly thermoplastic- and thermoset-based systems. Recently, studies in rubber/layered silicate nanocomposites were started, as well. It was presented how complex maybe the nanocomposite formation for the related systems. Therefore the rules governing their structure-property relationships have to be clarified. In this Thesis, the related aspects were addressed. For the investigations several ethylene propylene diene rubbers (EPDM) of polar and non-polar origin were selected, as well as, the more polar hydrogenated acrylonitrile butadiene rubber (HNBR). The polarity was found to be beneficial on the nanocomposite formation as it assisted to the intercalation of the polymer chains within the clay galleries. This favored the development of exfoliated structures. Finding an appropriate processing procedure, i.e. compounding in a kneader instead of on an open mill, the mechanical performance of the nanocomposites was significantly improved. The complexity of the nanocomposite formation in rubber/organoclay system was demonstrated. The deintercalation of the organoclay observed, was traced to the vulcanization system used. It was evidenced by an indirect way that during sulfur curing, the primary amine clay intercalant leaves the silicate surface and migrates in the rubber matrix. This was explained by its participation in the sulfur-rich Zn-complexes created. Thus, by using quaternary amine clay intercalants (as it was presented for EPDM or HNBR compounds) the deintercalation was eliminated. The organoclay intercalation/deintercalation detected for the primary amine clay intercalants, were controlled by means of peroxide curing (as it was presented for HNBR compounds), where the vulcanization mechanism differs from that of the sulfur curing. The current analysis showed that by selecting the appropriate organoclay type the properties of the nanocomposites can be tailored. This occurs via generating different nanostructures (i.e. exfoliated, intercalated or deintercalated). In all cases, the rubber/organoclay nanocomposites exhibited better performance than vulcanizates with traditional fillers, like silica or unmodified (pristine) layered silicates.The mechanical and gas permeation behavior of the respective nanocomposites were modelled. It was shown that models (e.g. Guth’s or Nielsen’s equations) developed for “traditional” vulcanizates can be used when specific aspects are taken into consideration. These involve characteristics related to the platy structure of the silicates, i.e. their aspect ratio after compounding (appearance of platelet stacks), or their orientation in the rubber matrix (order parameter)

Structure-Property Relationships in Rubber/Layered Silicate Nanocomposites

The scientific and industrial interest devoted to polymer/layered silicate nanocomposites due to their outstanding properties and novel applications resulted in numerous studies in the last decade. They cover mostly thermoplastic- and thermoset-based systems. Recently, studies in rubber/layered silicate nanocomposites were started, as well. It was presented how complex maybe the nanocomposite formation for the related systems. Therefore the rules governing their structure-property relationships have to be clarified. In this Thesis, the related aspects were addressed. For the investigations several ethylene propylene diene rubbers (EPDM) of polar and non-polar origin were selected, as well as, the more polar hydrogenated acrylonitrile butadiene rubber (HNBR). The polarity was found to be beneficial on the nanocomposite formation as it assisted to the intercalation of the polymer chains within the clay galleries. This favored the development of exfoliated structures. Finding an appropriate processing procedure, i.e. compounding in a kneader instead of on an open mill, the mechanical performance of the nanocomposites was significantly improved. The complexity of the nanocomposite formation in rubber/organoclay system was demonstrated. The deintercalation of the organoclay observed, was traced to the vulcanization system used. It was evidenced by an indirect way that during sulfur curing, the primary amine clay intercalant leaves the silicate surface and migrates in the rubber matrix. This was explained by its participation in the sulfur-rich Zn-complexes created. Thus, by using quaternary amine clay intercalants (as it was presented for EPDM or HNBR compounds) the deintercalation was eliminated. The organoclay intercalation/deintercalation detected for the primary amine clay intercalants, were controlled by means of peroxide curing (as it was presented for HNBR compounds), where the vulcanization mechanism differs from that of the sulfur curing. The current analysis showed that by selecting the appropriate organoclay type the properties of the nanocomposites can be tailored. This occurs via generating different nanostructures (i.e. exfoliated, intercalated or deintercalated). In all cases, the rubber/organoclay nanocomposites exhibited better performance than vulcanizates with traditional fillers, like silica or unmodified (pristine) layered silicates.The mechanical and gas permeation behavior of the respective nanocomposites were modelled. It was shown that models (e.g. Guth’s or Nielsen’s equations) developed for “traditional” vulcanizates can be used when specific aspects are taken into consideration. These involve characteristics related to the platy structure of the silicates, i.e. their aspect ratio after compounding (appearance of platelet stacks), or their orientation in the rubber matrix (order parameter)

Binarization of Textual Content in Video Frames

In this paper we present a binarization technique for textual content in video frames which can be applied in the resulting image of the text detection step aiming in an improved OCR performance. The proposed technique is based on the detection of the text baselines in order to define the main body of the text. The main body of the text is used to detect the stroke width of the characters which will address the two consecutive locally adaptive binarization steps that follow. At the first step, we use different valuation in parameters for the inside and outside area of the main body of the text. To include the thinned or broken binarized parts that may exist outside the main text body, convex hull analysis is performed so that the entire text body is considered. At the second step, binarization is performed with different valuation in parameters for the inside and outside area of the entire text body. The effectiveness of the proposed technique is demonstrated by both qualitative and OCR-based evaluation