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Δημοσιεύσεις σε Διεθνή Περιοδικά (Journals)


Copyright Notice: This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted or mass reproduced without the explicit permission of the copyright holder.


E. Kavallieratou, L Likforman-Sulem, N. Vasilopoulos, Slant Removal Technique for Historical Document Images, Journal of Imaging, Vol. 4, No. 6, pp. 80, 2018, Multidisciplinary Digital Publishing Institute,
 

Abstract
Slanted text has been demonstrated to be a salient feature of handwriting. Its estimation is a necessary preprocessing task in many document image processing systems in order to improve the required training. This paper describes and evaluates a new technique for removing the slant from historical document pages that avoids the segmentation procedure into text lines and words. The proposed technique first relies on slant angle detection from an accurate selection of fragments. Then, a slant removal technique is applied. However, the presented slant removal technique may be combined with any other slant detection algorithm. Experimental results are provided for four document image databases: two historical document databases, the TrigraphSlant database (the only database dedicated to slant removal), and a printed database in order to check the precision of the proposed technique.

N. Vasilopoulos, E. Kavallieratou, Unified layout analysis and text localization framework, Journal of Electronic Imaging, Vol. 26, No. 1, pp. 013009, 2017, International Society for Optics and Photonics,
 

Abstract
A technique appropriate for extracting textual information from documents with complex layouts, such as newspapers and journals, is presented. It is a combination of a foreground analysis and a text localization method. The first one is used to segment the page in text and nontext blocks, whereas the second one is used to detect text that may be embedded inside images, charts, diagrams, tables, etc. Detailed experiments on two public databases showed that mixing layout analysis and text localization techniques can lead to improved page segmentation and text extraction results.

N. Vasilopoulos, E. Kavallieratou, Complex layout analysis based on contour classification and morphological operations, Engineering Applications of Artificial Intelligence, Vol. 65, pp. 220-229, 2017, Pergamon,
 

Abstract
In this paper, a hybrid technique for complex layout analysis is presented. Morphological operations are applied to both the foreground and the background, in order to connect neighboring regions and detect separator lines and columns respectively. Contour tracing is used for the extraction of shape and size information and classification of the connected components. Evaluated on the RDCL-2015 dataset, the method achieved state-of-art results in less than three seconds per page.

Επιστημονικά Συνέδρια (Conferences)


Copyright Notice: This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted or mass reproduced without the explicit permission of the copyright holder.


N. Vasilopoulos, Yazan Wasfi, E. Kavallieratou, Automatic Text Extraction from Arabic Newspapers, International Conference Image Analysis and Recognition, Springer, Cham, pp. 505-510, Dec, 2018,
 

Abstract
A system for extracting the textual information from document images with complex layouts is presented. It is based on both layout analysis and text localization techniques. Layout analysis is first applied to segment the page in text and non-text blocks and then text localization is used to detect text that may be embedded inside images, charts, diagrams, tables etc. Detailed experiments on scanned Arabic newspapers showed that combining layout analysis and text localization methods can lead to improved page segmentation and text extraction results.

Ankit Kumar Sah, Showmik Bhowmik, Samir Malakar, Ram Sarkar, E. Kavallieratou, N. Vasilopoulos, Text and non-text recognition using modified HOG descriptor, 2017 IEEE Calcutta Conference (CALCON), IEEE, pp. 64-68, Dec, 2017,
 

Abstract
In order to convert a document image in its editable version, an OCR engine must identify and separate the nontext regions from text regions of a given document image. In the present work, a technique is developed to classify various text and non-text regions present in a document image. For that purpose, a modified version of Histogram of Oriented Gradient (HOG) is used as a feature descriptor. Multi-Layer Perceptron (MLP) is chosen from a pool of classifier by comparing the recognition accuracy of it with two other well-known classifiers viz., Random Forest (RF), Nave Bayes (NB). The designed technique is evaluated on a dataset, containing 862 images of manually extracted regions from two standard databases namely, RDCL2015 dataset and Media Team Document dataset. The proposed system has achieved 96.44% recognition accuracy and outperformed some of the state-of-the-art feature descriptors …

Βιβλία


Copyright Notice: This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted or mass reproduced without the explicit permission of the copyright holder.


Κεφάλαια σε Βιβλία


Copyright Notice: This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted or mass reproduced without the explicit permission of the copyright holder.


Επιμέλεια Πρακτικών Διεθνών Συνεδρίων


Copyright Notice: This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted or mass reproduced without the explicit permission of the copyright holder.