Ακαδημαϊκό Προσωπικό
Καβαλλιεράτου Εργίνα
Προσωπικά Στοιχεία
Καβαλλιεράτου Εργίνα
Καθηγήτρια
kavallieratou [at] aegean [dot] gr
2273082263
17 ή εργαστήριο Ρομποτικής
Πέμπτη 15.00-17.00 στο εργαστήριο Ρομποτικής (στείλτε email για ραντεβού)
Copyright Notice: Το υλικό αυτό παρουσιάζεται για έγκαιρη διάδοση επιστημονικής και τεχνικής εργασίας. Τα πνευματικά δικαιώματα και όλα τα σχετικά δικαιώματα παραμένουν στους συγγραφείς ή σε άλλους κατόχους πνευματικών δικαιωμάτων. Όσοι αντιγράφουν αυτές τις πληροφορίες αναμένεται να τηρούν τους όρους και τους περιορισμούς που επιβάλλει το πνευματικό δικαίωμα κάθε συγγραφέα. Στις περισσότερες περιπτώσεις, τα έργα αυτά δεν μπορούν να αναδημοσιευτούν ή να αναπαραχθούν μαζικά χωρίς τη ρητή άδεια του κατόχου των πνευματικών δικαιωμάτων.
Επιστημονικά Συνέδρια
N. Manos, M. Vasileiou, E. Kavallieratou, Building Kalypso: The Construction, 5th International Conference on Advances in Signal Processing and Artificial Intelligence (ASPAI' 2023), Sergey Y. Yurish, (ed), pp. 195-198, Jun, 2023, Tenerife (Canary Islands), Spain, IFSA, http://dx.doi.org/10.13140/RG.2.2.27945....
Περίληψη:
Underwater vehicles can play an essential role in fish farming and their construction can be a challenging aspect of their development owing to the necessity of waterproofing electronic components. This paper describes the construction and basic framework of a robotic vehicle named "Kalypso," which was developed to inspect nets in fish farms. Kalypso can distinguish between clean areas on the net and areas that are either torn or covered in algae, based on an algorithm. Also, it is equipped with sensors to estimate position, depth, temperature and leakage, which can detect water in the watertight housing. The watertight part of the robot includes cable plugs, some of which are detachable to facilitate the connection of various devices, such as sensors and lights. Kalypso has two cameras, one facing the front and another facing the bottom. Furthermore, the robot has underwater ultrasonic sensors, which measure the distance from the environment, and LED lights on the front for increased visibility in low-light environments. Several tests were carried out, both inside fish farm nets and in the open sea.
Underwater vehicles can play an essential role in fish farming and their construction can be a challenging aspect of their development owing to the necessity of waterproofing electronic components. This paper describes the construction and basic framework of a robotic vehicle named "Kalypso," which was developed to inspect nets in fish farms. Kalypso can distinguish between clean areas on the net and areas that are either torn or covered in algae, based on an algorithm. Also, it is equipped with sensors to estimate position, depth, temperature and leakage, which can detect water in the watertight housing. The watertight part of the robot includes cable plugs, some of which are detachable to facilitate the connection of various devices, such as sensors and lights. Kalypso has two cameras, one facing the front and another facing the bottom. Furthermore, the robot has underwater ultrasonic sensors, which measure the distance from the environment, and LED lights on the front for increased visibility in low-light environments. Several tests were carried out, both inside fish farm nets and in the open sea.
E. Kavallieratou, Konstantinos Paraskevas, M. Vasileiou, Building Kalypso: The Software, 2023 7th International Conference on Robotics and Automation Sciences (ICRAS), Jun, 2023, Wuhan, China, IEEE, https://doi.org/10.1109/ICRAS57898.2023....
Περίληψη:
In this paper, the software of Kalypso, an underwater robot designed for fisheries is presented. The software that controls the robot's movements and data processing is a critical component of its operation, and this paper provides a detailed analysis of the algorithms used to ensure reliable performance. The results of this analysis provide valuable insights for researchers and engineers working to improve the efficiency and effectiveness of underwater robots in the context of fisheries management.
In this paper, the software of Kalypso, an underwater robot designed for fisheries is presented. The software that controls the robot's movements and data processing is a critical component of its operation, and this paper provides a detailed analysis of the algorithms used to ensure reliable performance. The results of this analysis provide valuable insights for researchers and engineers working to improve the efficiency and effectiveness of underwater robots in the context of fisheries management.
M. Vasileiou, N. Manos, E. Kavallieratou, An Underwater Vehicle for Aquaculture Inspection, 7th International Conference on Control, Automation and Diagnosis (ICCAD’23), May, 2023, Rome, Italy, IEEE, https://doi.org/10.1109/ICCAD57653.2023....
Περίληψη:
A significant challenge in fish farms is net cage deterioration, which leads to fish escapes owing to holes and can have a severe influence on the fish's health due to biofouling. To reduce fish losses, divers are utilized on a weekly basis by fisheries to carry out the task of inspecting the net cages. Companies that are involved in aquaculture are always seeking for methods to increase their profits, and one of those ways is to cut down on the costs of maintenance. This paper is about the development of an unmanned underwater vehicle used for inspection in net cages at Kefalonia Fisheries in Greece. This vehicle has a 3D-printed body and a six-thruster configuration, featuring five degrees of freedom. The vehicle's primary goal is to reduce divers’ expenses by conducting inspections more frequently. In this work, the design, manufacture, and control are presented along with the experimental results and flow simulation of the vehicle. The suggested design is versatile and robust while yet being affordable, and the fisheries may easily adopt it due to its inexpensive price and simplicity of operation.
A significant challenge in fish farms is net cage deterioration, which leads to fish escapes owing to holes and can have a severe influence on the fish's health due to biofouling. To reduce fish losses, divers are utilized on a weekly basis by fisheries to carry out the task of inspecting the net cages. Companies that are involved in aquaculture are always seeking for methods to increase their profits, and one of those ways is to cut down on the costs of maintenance. This paper is about the development of an unmanned underwater vehicle used for inspection in net cages at Kefalonia Fisheries in Greece. This vehicle has a 3D-printed body and a six-thruster configuration, featuring five degrees of freedom. The vehicle's primary goal is to reduce divers’ expenses by conducting inspections more frequently. In this work, the design, manufacture, and control are presented along with the experimental results and flow simulation of the vehicle. The suggested design is versatile and robust while yet being affordable, and the fisheries may easily adopt it due to its inexpensive price and simplicity of operation.
M. Rousouliotis, M. Vasileiou, N. Manos, E. Kavallieratou, Using a Robot to Teach Python, 14th International Conference on Robotics in Education (RiE), Balogh, R., Obdržálek, D., Christoforou, E., (ed), Apr, 2023, Limassol, Cyprus, Springer, https://doi.org/10.1007/978-3-031-38454-...
Περίληψη:
Educational robotics is rooted in Constructionism and allows learners to investigate and discover new concepts. It would appear that learning a programming language while programming a robot is more motivating and productive than conventional methods. El Greco platform is an educational platform built to teach Python. Users can control El Greco from any computer connected to the Internet due to the platform’s web-based interface. El Greco is a social humanoid robot built to be affordable and appropriate for use in education. Potential users can use Python direct code entry or the Blockly library to control El Greco. The Blockly library embeds an editor in an application to represent coding notions like interlocking blocks. Unique functions that control El Greco were created. The inserted code can be executed on the website or by the Robot. The user can view the result of code execution through a live-streaming window. The El Greco platform has been designed with students in mind but is available to anyone at no cost.
Educational robotics is rooted in Constructionism and allows learners to investigate and discover new concepts. It would appear that learning a programming language while programming a robot is more motivating and productive than conventional methods. El Greco platform is an educational platform built to teach Python. Users can control El Greco from any computer connected to the Internet due to the platform’s web-based interface. El Greco is a social humanoid robot built to be affordable and appropriate for use in education. Potential users can use Python direct code entry or the Blockly library to control El Greco. The Blockly library embeds an editor in an application to represent coding notions like interlocking blocks. Unique functions that control El Greco were created. The inserted code can be executed on the website or by the Robot. The user can view the result of code execution through a live-streaming window. The El Greco platform has been designed with students in mind but is available to anyone at no cost.
M. Vasileiou, N. Manos, E. Kavallieratou, IURA: An Inexpensive Underwater Robotic Arm for Kalypso ROV, 2022 IEEE International Conference on Electrical, Computer, Communications and Mechatronics Engineering (ICECCME), pp. 832-837, Nov, 2022, Male, Maldives, IEEE, https://doi.org/10.1109/ICECCME55909.202...
Περίληψη:
Remotely Operated Underwater Vehicles (ROVs) used in net cages at fish farms are usually employed to inspect net wear and biofouling. Implementing a robotic system to repair the damages can reduce diver costs and can be lucrative for the aquaculture company. This paper presents the design, fabrication, and modeling of an affordable subsea robotic arm called IURA, that can be integrated to any underwater vehicle. For this study Kalypso ROV was used. Although IURA is at its infancy, it features (i) high modularity allowing to change end-effector tool effortlessly, and (ii) lowcost which makes it feasible for any ROV integration. It is mostly 3D-printed and has two servo motors as joints featuring 2 Degrees of Freedom (DoF). Two manipulators were tested, one to dispose fish morts, and another to remove objects from the net cages at fish farms. In this work, the design of IURA will be presented along with the fabrication and sealing of the arm. Furthermore, the modeling of the robotic arm will be quoted and flow simulation of both end-effectors. Finally, the experimental results will be discussed. The proposed design features customizability and sturdiness while retaining low-cost and can be used for subsea operations at Kefalonia Fisheries’ net cages when mounted on Kalypso ROV.
Remotely Operated Underwater Vehicles (ROVs) used in net cages at fish farms are usually employed to inspect net wear and biofouling. Implementing a robotic system to repair the damages can reduce diver costs and can be lucrative for the aquaculture company. This paper presents the design, fabrication, and modeling of an affordable subsea robotic arm called IURA, that can be integrated to any underwater vehicle. For this study Kalypso ROV was used. Although IURA is at its infancy, it features (i) high modularity allowing to change end-effector tool effortlessly, and (ii) lowcost which makes it feasible for any ROV integration. It is mostly 3D-printed and has two servo motors as joints featuring 2 Degrees of Freedom (DoF). Two manipulators were tested, one to dispose fish morts, and another to remove objects from the net cages at fish farms. In this work, the design of IURA will be presented along with the fabrication and sealing of the arm. Furthermore, the modeling of the robotic arm will be quoted and flow simulation of both end-effectors. Finally, the experimental results will be discussed. The proposed design features customizability and sturdiness while retaining low-cost and can be used for subsea operations at Kefalonia Fisheries’ net cages when mounted on Kalypso ROV.
M. Vasileiou, N. Manos, E. Kavallieratou, A Low-Cost 3D Printed Mini Underwater Vehicle: Design and Fabrication, 2021 IEEE 20th International Conference on Advanced Robotics (ICAR), pp. 390-395, Dec, 2021, Ljubljana, Slovenia, IEEE, https://doi.org/10.1109/ICAR53236.2021.9...
Περίληψη:
This paper introduces the conception, design, fabrication, and control of a modular remotely operated underwater vehicle. It is an affordable submarine robot intended for inspection operations in shallow depths. It has a 3D-Printed hull, and it can be adjusted according to the respective needs. It is equipped with six thrusters which allow it to have five Degrees of Freedom enabling increased maneuverability while it operates. The robot has marginally positive buoyancy which allows it to emerge in case of a malfunction, and the fins attached to the motors enhance its stability. The design, development, and construction as well as the components and electronics of the vehicle are presented. Moreover, the forces acting on the ROV and the buoyancy are introduced, along with the motion generation of the motors. The IMU sensor calibration is explained and a dataset of the rotational movement was analyzed into 3 axes. The proposed design features low cost, customizability and sturdiness allowing the user to configure and operate by himself.
This paper introduces the conception, design, fabrication, and control of a modular remotely operated underwater vehicle. It is an affordable submarine robot intended for inspection operations in shallow depths. It has a 3D-Printed hull, and it can be adjusted according to the respective needs. It is equipped with six thrusters which allow it to have five Degrees of Freedom enabling increased maneuverability while it operates. The robot has marginally positive buoyancy which allows it to emerge in case of a malfunction, and the fins attached to the motors enhance its stability. The design, development, and construction as well as the components and electronics of the vehicle are presented. Moreover, the forces acting on the ROV and the buoyancy are introduced, along with the motion generation of the motors. The IMU sensor calibration is explained and a dataset of the rotational movement was analyzed into 3 axes. The proposed design features low cost, customizability and sturdiness allowing the user to configure and operate by himself.
K. Karampidis, E. Linardos, E. Kavallieratou, StegoPass – Utilization of Steganography to Produce a Novel Unbreakable Biometric Based Password Authentication Scheme, Computational Intelligence in Security for Information Systems Conference, Sep, 2021, Springer, Cham
Περίληψη:
In the digital era we live, trustworthy verification schemes are required to ensure security and to authenticate the identity of an individual. Traditional passwords were proved to be highly vulnerable to attacks and the need of adopting new verification schemes is compulsory. Biometric factors have gained a lot of interest during the last years due to their uniqueness, ease of use, user convenience, and ease of deployment. However, recent research showed that even this unique authentication factors are not inviolable techniques. Thus, it is necessary to employ new verification schemes that cannot be replicated or stolen. In this paper we propose the utilization of steganography as a tool to provide unbreakable passwords. More specifically, we obtain a biometric feature of a user and embed it as a hidden message in an image. This image is then utilized as a password, the so-called StegoPass. Reversely, when a legit user or an attacker tries to unlock a device or an application, the same biometric feature is captured and embedded with the same steganography algorithm into the picture. The hash key of the resulted stego image in both cases is produced and if there is a complete match, user is considered as authenticated. To ensure that the proposed StegoPass cannot be replicated, we have conducted experiments with state-of-the-art deep learning algorithms. Moreover, it was examined whether Generative Adversarial Networks could produce exact copies of the StegoPass to fool the suggested method and the results showed that the proposed verification scheme is extremely secure.
In the digital era we live, trustworthy verification schemes are required to ensure security and to authenticate the identity of an individual. Traditional passwords were proved to be highly vulnerable to attacks and the need of adopting new verification schemes is compulsory. Biometric factors have gained a lot of interest during the last years due to their uniqueness, ease of use, user convenience, and ease of deployment. However, recent research showed that even this unique authentication factors are not inviolable techniques. Thus, it is necessary to employ new verification schemes that cannot be replicated or stolen. In this paper we propose the utilization of steganography as a tool to provide unbreakable passwords. More specifically, we obtain a biometric feature of a user and embed it as a hidden message in an image. This image is then utilized as a password, the so-called StegoPass. Reversely, when a legit user or an attacker tries to unlock a device or an application, the same biometric feature is captured and embedded with the same steganography algorithm into the picture. The hash key of the resulted stego image in both cases is produced and if there is a complete match, user is considered as authenticated. To ensure that the proposed StegoPass cannot be replicated, we have conducted experiments with state-of-the-art deep learning algorithms. Moreover, it was examined whether Generative Adversarial Networks could produce exact copies of the StegoPass to fool the suggested method and the results showed that the proposed verification scheme is extremely secure.
K. Karampidis, N. Vasilopoulos, Carlos Cuevas, Carlos R del-Blanco, E. Kavallieratou, Narciso García, Overview of the ImageCLEFsecurity 2019: File Forgery Detection Tasks, Conference and Labs of the Evaluation Forum, Sep, 2019
Περίληψη:
The File Forgery Detection tasks is in its first edition, in 2019. This year, it is composed by three subtasks: a) Forged file discovery, b) Stego image discovery and c) Secret message discovery. The data set contained 6,400 images and pdf files, divided into 3 sets. There were 61 participants and the majority of them participated in all the subtasks. This highlights the major concern the scientific community shows for security issues and the importance of each subtask. Submissions varied from a) 8, b) 31 and c) 14 submissions for each subtask, respectively. Although the datasets were small, most of the participants used deep learning techniques, especially in subtasks 2 & 3. The results obtained in subtask 3 -which was the most difficult one- showed that there is room for improvement, as more advanced techniques are needed to achieve better results. Deep learning techniques adopted by many researchers is a preamble in that direction, and proved that they may provide a promising steganalysis tool to a digital forensics examiner.
The File Forgery Detection tasks is in its first edition, in 2019. This year, it is composed by three subtasks: a) Forged file discovery, b) Stego image discovery and c) Secret message discovery. The data set contained 6,400 images and pdf files, divided into 3 sets. There were 61 participants and the majority of them participated in all the subtasks. This highlights the major concern the scientific community shows for security issues and the importance of each subtask. Submissions varied from a) 8, b) 31 and c) 14 submissions for each subtask, respectively. Although the datasets were small, most of the participants used deep learning techniques, especially in subtasks 2 & 3. The results obtained in subtask 3 -which was the most difficult one- showed that there is room for improvement, as more advanced techniques are needed to achieve better results. Deep learning techniques adopted by many researchers is a preamble in that direction, and proved that they may provide a promising steganalysis tool to a digital forensics examiner.
Bogdan Ionescu, Henning Müller, Renaud Péteri, Duc-Tien Dang-Nguyen, Luca Piras, Michael Riegler, Minh-Triet Tran, Mathias Lux, Cathal Gurrin, E. Kavallieratou, ImageCLEF 2019: Multimedia Retrieval in Lifelogging, Medical, Nature, and Security Applications, European Conference on Information Retrieval, Springer, Cham, pp. 301-308, 2019
Περίληψη:
This paper presents an overview of the foreseen ImageCLEF 2019 lab that will be organized as part of the Conference and Labs of the Evaluation Forum - CLEF Labs 2019. ImageCLEF is an ongoing evaluation initiative (started in 2003) that promotes the evaluation of technologies for annotation, indexing and retrieval of visual data with the aim of providing information access to large collections of images in various usage scenarios and domains. In 2019, the 17th edition of ImageCLEF will run four main tasks: (i) a Lifelog task (videos, images and other sources) about daily activities understanding, retrieval and summarization, (ii) a Medical task that groups three previous tasks (caption analysis, tuberculosis prediction, and medical visual question answering) with newer data, (iii) a new Coral task about segmenting and labeling collections of coral images for 3D modeling, and (iv) a new Security task …
This paper presents an overview of the foreseen ImageCLEF 2019 lab that will be organized as part of the Conference and Labs of the Evaluation Forum - CLEF Labs 2019. ImageCLEF is an ongoing evaluation initiative (started in 2003) that promotes the evaluation of technologies for annotation, indexing and retrieval of visual data with the aim of providing information access to large collections of images in various usage scenarios and domains. In 2019, the 17th edition of ImageCLEF will run four main tasks: (i) a Lifelog task (videos, images and other sources) about daily activities understanding, retrieval and summarization, (ii) a Medical task that groups three previous tasks (caption analysis, tuberculosis prediction, and medical visual question answering) with newer data, (iii) a new Coral task about segmenting and labeling collections of coral images for 3D modeling, and (iv) a new Security task …
Bogdan Ionescu, Henning Müller, Renaud Péteri, Yashin Dicente Cid, Vitali Liauchuk, Vassili Kovalev, Dzmitri Klimuk, Aleh Tarasau, Asma Ben Abacha, E. Kavallieratou, ImageCLEF 2019: Multimedia retrieval in medicine, lifelogging, security and nature, International Conference of the Cross-Language Evaluation Forum for European Languages, pp. 358-386, 2019, Springer, Cham
Περίληψη:
This paper presents an overview of the ImageCLEF 2019 lab, organized as part of the Conference and Labs of the Evaluation Forum - CLEF Labs 2019. ImageCLEF is an ongoing evaluation initiative (started in 2003) that promotes the evaluation of technologies for annotation, indexing and retrieval of visual data with the aim of providing information access to large collections of images in various usage scenarios and domains. In 2019, the 17th edition of ImageCLEF runs four main tasks: (i) a medical task that groups three previous tasks (caption analysis, tuberculosis prediction, and medical visual question answering) with new data, (ii) a lifelog task (videos, images and other sources) about daily activities understanding, retrieval and summarization, (iii) a new security task addressing the problems of automatically identifying forged content and retrieve hidden information, and (iv) a new coral task about …
This paper presents an overview of the ImageCLEF 2019 lab, organized as part of the Conference and Labs of the Evaluation Forum - CLEF Labs 2019. ImageCLEF is an ongoing evaluation initiative (started in 2003) that promotes the evaluation of technologies for annotation, indexing and retrieval of visual data with the aim of providing information access to large collections of images in various usage scenarios and domains. In 2019, the 17th edition of ImageCLEF runs four main tasks: (i) a medical task that groups three previous tasks (caption analysis, tuberculosis prediction, and medical visual question answering) with new data, (ii) a lifelog task (videos, images and other sources) about daily activities understanding, retrieval and summarization, (iii) a new security task addressing the problems of automatically identifying forged content and retrieve hidden information, and (iv) a new coral task about …
E. Kavallieratou, Carlos R del-Blanco, Carlos Cuevas, Narciso García, Interactive learning-based retrieval technique for visual lifelogging, International Conference of the Cross-Language Evaluation Forum for European Languages, Springer, Cham, pp. 226-237, 2019
Περίληψη:
Currently, there is a plethora of video wearable devices that can easily collect data from daily user life. This fact has promoted the development of lifelogging applications for security, healthcare, and leisure. However, the retrieval of not-pre-defined events is still a challenge due to the impossibility of having a potentially unlimited number of fully annotated databases covering all possible events. This work proposes an interactive and weakly supervised learning approach that is able of retrieving any kinds of events using general and weakly annotated databases. The proposed system has been evaluated with the database provided by the Lifelog Moment Retrieval (LMRT) challenge of ImageCLEF (Lifelog2018), where it reached the first position in the final ranking.
Currently, there is a plethora of video wearable devices that can easily collect data from daily user life. This fact has promoted the development of lifelogging applications for security, healthcare, and leisure. However, the retrieval of not-pre-defined events is still a challenge due to the impossibility of having a potentially unlimited number of fully annotated databases covering all possible events. This work proposes an interactive and weakly supervised learning approach that is able of retrieving any kinds of events using general and weakly annotated databases. The proposed system has been evaluated with the database provided by the Lifelog Moment Retrieval (LMRT) challenge of ImageCLEF (Lifelog2018), where it reached the first position in the final ranking.
Pavlos Skoupras, Maria Soulountsi, Shubham Khandelwal, Jaideep Upadhyay, Konstantinos Paraskevas, Georgios Zervas, N. Fourtounis, Dimitris Katsios, Giorgos Papamichalakis, E. Kavallieratou, El Greco: a 3d-printed humanoid that anybody can afford, Proceedings of the 10th Hellenic Conference on Artificial Intelligence, ACM, pp. 58, 2018
Περίληψη:
In this paper, the humanoid robot named El Greco is presented (design, hardware and software). The humanoids from DARPA Robotics Challenge inspired us in many aspects, while at the same time the goal was to maintain a low cost and build a humanoid accordingly, so that we can create a model that is affordable and easy to build in order to be used by the youth. The entire assembly of the robot consists of parts such as limbs, head, body, legs and the base which are 3D printed. All the details over the design specifications and the problems incurred during the development of the humanoid are described under each module of the humanoid. Further details and results are given over the open source software of El Greco.
In this paper, the humanoid robot named El Greco is presented (design, hardware and software). The humanoids from DARPA Robotics Challenge inspired us in many aspects, while at the same time the goal was to maintain a low cost and build a humanoid accordingly, so that we can create a model that is affordable and easy to build in order to be used by the youth. The entire assembly of the robot consists of parts such as limbs, head, body, legs and the base which are 3D printed. All the details over the design specifications and the problems incurred during the development of the humanoid are described under each module of the humanoid. Further details and results are given over the open source software of El Greco.
Ioanna Bakali, D. Chatzis, Nikolaos Mavropoulos, N. Fourtounis, Maria Soulountsi, N. Manos, Aristotelis Theodoulidis, Panagiotis Papanastasiou, E. Kavallieratou, Control a robot via internet using a block programming platform for educational purposes, Proceedings of the 10th Hellenic Conference on Artificial Intelligence, ACM, pp. 59, 2018
Περίληψη:
This paper deals with a system consisting of a robot named El Greco that can be programmed via internet and livestreaming from any place, anywhere, to move on a play room as well as perform other functions such as to produce voice in many languages, recognize voice commands, recognize faces, perceive its environment, perform combined movements and provide information by searching the Internet. All these capabilities of the robot can be programmed using a friendly block programming platform that has been developed to be used by students for educational purposes. The system was used by a number of students and the results of two questionnaires before and after the use are reported.
This paper deals with a system consisting of a robot named El Greco that can be programmed via internet and livestreaming from any place, anywhere, to move on a play room as well as perform other functions such as to produce voice in many languages, recognize voice commands, recognize faces, perceive its environment, perform combined movements and provide information by searching the Internet. All these capabilities of the robot can be programmed using a friendly block programming platform that has been developed to be used by students for educational purposes. The system was used by a number of students and the results of two questionnaires before and after the use are reported.
N. Vasilopoulos, Yazan Wasfi, E. Kavallieratou, Automatic Text Extraction from Arabic Newspapers, International Conference Image Analysis and Recognition, Springer, Cham, pp. 505-510, 2018
Περίληψη:
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.
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.
E. Kavallieratou, Carlos R del-Blanco, Carlos Cuevas, Narciso García, Retrieving Events in Life Logging, CLEF (Working Notes), 2018
Περίληψη:
This paper describes our contribution for the Lifelog Moment Retrieval (LMRT) challenge of ImageCLEF Lifelog2018. Lifelogging has a tremendous potential in many applications. However, the wide range of possible moment events along with the lack of fully annotated databases make this task very challenging. This work proposes an interactive and weakly supervised learning approach that can dramatically reduce the time to retrieve any kind of events in huge databases. Impressive results have been obtained in the referred challenge, reaching the first rank.
This paper describes our contribution for the Lifelog Moment Retrieval (LMRT) challenge of ImageCLEF Lifelog2018. Lifelogging has a tremendous potential in many applications. However, the wide range of possible moment events along with the lack of fully annotated databases make this task very challenging. This work proposes an interactive and weakly supervised learning approach that can dramatically reduce the time to retrieve any kind of events in huge databases. Impressive results have been obtained in the referred challenge, reaching the first rank.
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, 2017
Περίληψη:
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 …
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 …
P. Diamantatos, E. Kavallieratou, Android Based Electronic Travel Aid System for Blind People, AIAI 2014 Artificial Intelligence Applications and Innovations, pp. 585-592, Sep, 2014, Rhodes, Greece, Springer Berlin Heidelberg, http://delab.csd.auth.gr/aiai2014/
Περίληψη:
Blindness is the condition of lacking visual perception due to physiological or neurological factors. Blind people do not have the full perception of the surrounding environment, though navigating, in an unknown environment or/and with obstacles on route, can be a very difficult task. In this paper, an information mobile system is presented, that acts as an electronic travel aid, and can guide a blind person through a route, inform him about imminent obstacles in his path and help him orientate himself. The current prototype consists of a mobile phone, and the developed application.
Blindness is the condition of lacking visual perception due to physiological or neurological factors. Blind people do not have the full perception of the surrounding environment, though navigating, in an unknown environment or/and with obstacles on route, can be a very difficult task. In this paper, an information mobile system is presented, that acts as an electronic travel aid, and can guide a blind person through a route, inform him about imminent obstacles in his path and help him orientate himself. The current prototype consists of a mobile phone, and the developed application.
P. Diamantatos, E. Kavallieratou, P Gomez-Gil, Binarization: a Tool for Text Localization, ICFHR 2014 14th International Conference on Frontiers in Handwriting Recognition, J. Llados, R. Manmatha, C. - L. Tan, (eds), Sep, 2014, Crete, Greece, ICFHR, http://www.icfhr2014.org/
Περίληψη:
This paper presents a novel procedure for localizing text on scene photos. It takes advantage of the fact that text should present some contrast in comparison with the background, in order to be distinguished by the human eye. A procedure of binarization is applied in order to create appropriate images for the text detection. The connected components of the image are extracted and some heuristic rules are applied in order to identify areas containing text. Finally, the overlaps are handled and the false detections are rejected. The method is evaluated using images of natural scene taken from the robust reading competition of ICDAR2011. The results are promising and some useful conclusions are drawn.
This paper presents a novel procedure for localizing text on scene photos. It takes advantage of the fact that text should present some contrast in comparison with the background, in order to be distinguished by the human eye. A procedure of binarization is applied in order to create appropriate images for the text detection. The connected components of the image are extracted and some heuristic rules are applied in order to identify areas containing text. Finally, the overlaps are handled and the false detections are rejected. The method is evaluated using images of natural scene taken from the robust reading competition of ICDAR2011. The results are promising and some useful conclusions are drawn.
P. Diamantatos, E. Kavallieratou, S. Gritzalis, Writer Identification using Statistical and Model Based Approach, ICFHR 2014 14th International Conference on Frontiers in Handwriting Recognition, J. Llados, R. Manmatha, C. - L. Tan, (eds), pp. 589-594, Sep, 2014, Crete, Greece, ICFHR , http://www.icfhr2014.org/
Περίληψη:
The state-of-the-art writer identification systems use a variety of different features and techniques in order to identify the writer of the handwritten text. In this paper several statistical and model based features are presented. Specifically, an improvement of a statistical feature, the edge hinge distribution, is attempted. Furthermore, the combination of this feature with a model-based feature is explored, that is based on a codebook of graphemes. For the evaluation, the Firemaker DB was used, which consists of 250 writers, including 4 pages per writer. The best result for the statistical suggested approach, the skeleton hinge distribution, achieved accuracy of 90,8%, while the combination of this method with the codebook of graphemes reached 96%.
The state-of-the-art writer identification systems use a variety of different features and techniques in order to identify the writer of the handwritten text. In this paper several statistical and model based features are presented. Specifically, an improvement of a statistical feature, the edge hinge distribution, is attempted. Furthermore, the combination of this feature with a model-based feature is explored, that is based on a codebook of graphemes. For the evaluation, the Firemaker DB was used, which consists of 250 writers, including 4 pages per writer. The best result for the statistical suggested approach, the skeleton hinge distribution, achieved accuracy of 90,8%, while the combination of this method with the codebook of graphemes reached 96%.
Λήψη PDF[1]
P. Diamantatos, V.Verras, E. Kavallieratou, Detecting Main Body Size in Document Images., ICDAR, pp. 1160-1164, 2013
[2]
P.Diamantatos, V.Verras, E. Kavallieratou, Detecting Main Body Size in Document Images, Document Analysis and Recognition (ICDAR), 2013 12th International Conference on. IEEE, 2013., 2013
[3]
N.Vasilopoulos, E. Kavallieratou, A classification-free word-spotting system, IS&T/SPIE Electronic Imaging. International Society for Optics and Photonics, 2013
K. Prokopiou, E. Kavallieratou, E. Stamatatos, An Image Processing Self-training System for Ruling Line Removal Algorithms, 18th Int. Conf. on Digital Signal Processing (DSP), 2013, IEEE
Περίληψη:
Ruling line removal is an important pre-processing step in document image processing. Several algorithms have been proposed for this task. However, it is important to be able to take full advantage of the existing algorithms by adapting them to the specific properties of a document image collection. In this paper, a system is presented, appropriate for fine-tuning the parameters of ruling line removal algorithms or appropriately adapt them to a specific document image collection, in order to improve the results. The application of our method to an existed line removal algorithms is presented.
Ruling line removal is an important pre-processing step in document image processing. Several algorithms have been proposed for this task. However, it is important to be able to take full advantage of the existing algorithms by adapting them to the specific properties of a document image collection. In this paper, a system is presented, appropriate for fine-tuning the parameters of ruling line removal algorithms or appropriately adapt them to a specific document image collection, in order to improve the results. The application of our method to an existed line removal algorithms is presented.
[1]
E.Matthaiou, E. Kavallieratou, An information extraction system from patient historical documents, Proceedings of the 27th Annual ACM Symposium on Applied Computing, , pp. 787-791, 2012
[1]
S.Vavilis, E. Kavallieratou, A tool for tuning binarization techniques, International Conference on Document Analysis and Recognition (ICDAR), 2011
[2]
E. Kavallieratou, D. Lopresti, C. Chen, Ruling line detection and removal, Proceedings of SPIE 7874, 78740V, 2011
[1]
R Paredes, E. Kavallieratou, RD Lins, ICFHR 2010 contest: Quantitative evaluation of binarization algorithms, 2010 International Conference Frontiers in Handwriting Recognition (ICFHR), , 2010
[2]
C. Chen, D. Lopresti, E. Kavallieratou, The Impact of Ruling Lines on Writer Identification, 2010 International Conference Frontiers in Handwriting Recognition (ICFHR), , 2010
[3]
E. Kavallieratou, Text line detection and segmentation: uneven skew angles and hill-and-dale writing, In Proceedings of the 2010 ACM Symposium on Applied Computing (Sierre, Switzerland, March 22 - 26, 2010). SAC '10. ACM, New York, NY, pp. 59-60, 2010
[4]
D. Lopresti, E. Kavallieratou, Ruling Line Removal in Handwritten Page Images, IEEE Proc. of 20th International Conference of Pattern Recognition (ICPR 2010), pp. 2704-2707, 2010
J.Margaronis, M.Christou, E. Kavallieratou, Theodoros Tzouramanis, GCDB: a character database system, In Proceedings of the international Workshop on Multilingual OCR (Barcelona, Spain, July 25 - 25, 2009). ICDAE , 2009, ACM Press, <a target=_blank href=http://tinyurl.com/okhxrpj>http://tinyurl.com/okhxrpj</a>
Περίληψη:
In this article the GCDB (Greek Characters DataBase) System is presented. GCDB is a complete database system for storing images of Greek unconstrained handwritten characters. The three elements that compose this database are: a specialized input form, a database that contains the images of the filled forms and the software that allows the inputting of the data from the form into the database and their retrieval. The main purpose of this database system is to make it possible to achieve the automatic storage and organization of images of Greek symbols and letters in view of their use by OCR (Optical Character Recognition) systems or other applications. The GCDB system is designed within the concept of future expansion, providing an up to date database of Greek handwritten characters to cover the growing demands for offline character recognition of the Greek language.
In this article the GCDB (Greek Characters DataBase) System is presented. GCDB is a complete database system for storing images of Greek unconstrained handwritten characters. The three elements that compose this database are: a specialized input form, a database that contains the images of the filled forms and the software that allows the inputting of the data from the form into the database and their retrieval. The main purpose of this database system is to make it possible to achieve the automatic storage and organization of images of Greek symbols and letters in view of their use by OCR (Optical Character Recognition) systems or other applications. The GCDB system is designed within the concept of future expansion, providing an up to date database of Greek handwritten characters to cover the growing demands for offline character recognition of the Greek language.
[2]
N. Doulgeri, E. Kavallieratou, Retrieval of Historical Documents by Word Spotting, IS&T/SPIE Electronic Imaging 2009, 2009
[1]
K.Zagoris, E. Kavallieratou, N. Papamarkos, Developing Document Image Retrieval System, Proc. Of IADIS International Conference Computer Graphics and Visualization 2008, , pp. 119-126., 2008
[2]
E. Kavallieratou, An objective way to evaluate and compare binarization algorithms, 23rd Annual ACM Symposium on Applied Computing, 2008
[3]
P. Stathis, E. Kavallieratou, N. Papamarkos, An Evaluation Survey of Binarization Algorithms on Historical Documents, IEEE 19th International Conference on Pattern Recognition (ICPR'08), 2008
E. Kavallieratou, E. Stamatatos, Improving the Quality of Degraded Document Images, 2nd IEEE Int. Conf. on Document Image Analysis for Libraries (DIAL), pp. 340-349, 2006
Περίληψη:
It is common for libraries to provide public access to historical and ancient document image collections. It is common for such document images to require specialized processing in order to remove background noise and become more legible. In this paper, we propose a hybrid binarizatin approach for improving the quality of old documents using a combination of global and local thresholding. First, a global thresholding technique specifically designed for old document images is applied to the entire image. Then, the image areas that still contain background noise are detected and the same technique is re-applied to each area separately. Hence, we achieve better adaptability of the algorithm in cases where various kinds of noise coexist in different areas of the same image while avoiding the computational and time cost of applying a local thresholding in the entire image. Evaluation results based on a collection of historical document images indicate that the proposed approach is effective in removing background noise and improving the quality of degraded documents while documents already in good condition are not affected.
It is common for libraries to provide public access to historical and ancient document image collections. It is common for such document images to require specialized processing in order to remove background noise and become more legible. In this paper, we propose a hybrid binarizatin approach for improving the quality of old documents using a combination of global and local thresholding. First, a global thresholding technique specifically designed for old document images is applied to the entire image. Then, the image areas that still contain background noise are detected and the same technique is re-applied to each area separately. Hence, we achieve better adaptability of the algorithm in cases where various kinds of noise coexist in different areas of the same image while avoiding the computational and time cost of applying a local thresholding in the entire image. Evaluation results based on a collection of historical document images indicate that the proposed approach is effective in removing background noise and improving the quality of degraded documents while documents already in good condition are not affected.
E. Kavallieratou, E. Stamatatos, Adaptive Binarization of Historical Document Images, 18th Int. Conf. on Pattern Recognition, pp. 742-745, 2006
Περίληψη:
In this paper, we present a binarization technique specifically designed for historical document images. Existing methods for this problem focus on either finding a good global threshold or adapting the threshold for each area so that to remove smear, strains, uneven illumination etc. We propose a hybrid approach that first applies a global thresholding method and, then, identifies the image areas that are more likely to still contain noise. Each of these areas is re-processed separately to achieve better quality of binarization. We evaluate the proposed approach for different kinds of degradation problems. The results show that our method can handle hard cases while documents already in good condition are not affected drastically.
In this paper, we present a binarization technique specifically designed for historical document images. Existing methods for this problem focus on either finding a good global threshold or adapting the threshold for each area so that to remove smear, strains, uneven illumination etc. We propose a hybrid approach that first applies a global thresholding method and, then, identifies the image areas that are more likely to still contain noise. Each of these areas is re-processed separately to achieve better quality of binarization. We evaluate the proposed approach for different kinds of degradation problems. The results show that our method can handle hard cases while documents already in good condition are not affected drastically.
[1]
E. Kavallieratou, A Binarization Algorithm specialized on Document Images and Photos, 8th International Conference of Document Analysis and Recognition (ICDAR 2005), pp. 463-467, 2005, Seoul
[2]
E. Kavallieratou, H. Antonopoulou, Cleaning and Enhancing Historical Document Images, Advanced Concepts for Intelligent Vision Systems, pp. 681-688, 2005, Springer-Verlag
E. Stamatatos, E. Kavallieratou, Music Performer Verification Based on Learning Ensembles, Methods and Applications of Artificial Intelligence, G. Vouros, (ed), pp. 122 – 131, 2004
Περίληψη:
In this paper the problem of music performer verification is introduced. Given a certain performance of a musical piece and a set of candidate pianists the task is to examine whether or not a particular pianist is the actual performer. A database of 22 pianists playing pieces by F. Chopin in a computercontrolled piano is used in the presented experiments. An appropriate set of features that captures the idiosyncrasies of music performers is proposed. Wellknown machine learning techniques for constructing learning ensembles are applied and remarkable results are described in verifying the actual pianist, a very difficult task even for human experts.
In this paper the problem of music performer verification is introduced. Given a certain performance of a musical piece and a set of candidate pianists the task is to examine whether or not a particular pianist is the actual performer. A database of 22 pianists playing pieces by F. Chopin in a computercontrolled piano is used in the presented experiments. An appropriate set of features that captures the idiosyncrasies of music performers is proposed. Wellknown machine learning techniques for constructing learning ensembles are applied and remarkable results are described in verifying the actual pianist, a very difficult task even for human experts.
[2]
E. Kavallieratou, S. Stamatatos, H. Antonopoulou, Machine-Printed from Handwritten Text Discrimination, 9th Int’l Workshop on Frontiers in Handwriting Recognition (IWFHR-9), pp. 312-316, 2004
E. Kavallieratou, E. Stamatatos, Discrimination of Machine-Printed from Handwritten Text Using Simple Structural Characteristics, 17th International Conference on Pattern Recognition (ICPR 2004), 2004
Περίληψη:
In this paper, we present a trainable approach to discriminate between machine-printed and handwritten text. An integrated system able to localize text areas and split them in text-lines is used. A set of simple and easyto- compute structural characteristics that capture the differences between machine-printed and handwritten text-lines is introduced. Experiments on document images taken from IAM-DB and GRUHD databases show a remarkable performance of the proposed approach that requires minimal training data.
In this paper, we present a trainable approach to discriminate between machine-printed and handwritten text. An integrated system able to localize text areas and split them in text-lines is used. A set of simple and easyto- compute structural characteristics that capture the differences between machine-printed and handwritten text-lines is introduced. Experiments on document images taken from IAM-DB and GRUHD databases show a remarkable performance of the proposed approach that requires minimal training data.
[1]
M. Maragoudakis, E. Kavallieratou, N. Fakotakis, G. Kokkinakis, An Effective Stochastic Estimation of Handwritten Character Segmentation Bounds, ISAP 2003: Competitive Environment, Renewable Energy, Distributed Generation, Aug, 2003, Lemnos, Greece
[2]
E. Kavallieratou, K. Sgarbas, N. Fakotakis, G. Kokkinakis, Handwritten Word Recognition based on Structural Characteristics and Lexical Support, ICDAR 2003, pp. 562-566, Aug, 2003, Edinburgh, Scotland
[1]
S. Moeller, E. Kavallieratou, Diagnostic Assessment of Telephone Transmission Impact on ASR Performance and Human-to-Human Speech Quality, 3rd Int. Conf. on Language Resources and Evaluation (LREC 2002), pp. 1177-1184, 2002, ES-Las Palmas
[2]
E. Kavallieratou, N. Fakotakis, G. Kokkinakis, Handwritten Character Recognition based on Structural Characteristics, 16th International Conference of the International Association of Pattern Recognition ICPR 2002, pp. 139-142, 2002, Quebec-Canada
[3]
N. Liolios, E. Kavallieratou, N. Fakotakis, G. Kokkinakis, A New Shape Transformation Approach to Handwritten Character Recognition, 16th International Conference of the International Association of Pattern Recognition ICPR 2002, pp. 584-587, 2002, Quebec-Canada
[4]
M. Maragoudakis, E. Kavallieratou, N. Fakotakis, Incorporating Conditional Independence Assumption with Support Vector Machines to enhance Handwritten Character Segmentation Performance, 16th International Conference of the International Association of Pattern Recognition ICPR 2002, pp. 911-914, 2002, Quebec-Canada
[5]
M. Maragoudakis, E. Kavallieratou, N. Fakotakis, Improving handwritten character segmentation by incorporating Bayesian knowledge with support vector machines, IEEE Int. Conf. Audio Speech & Signal Processing ICASSP2002, 2002, Orlando-Florida
[1]
M. Maragoudakis, E. Kavallieratou, N. Fakotakis, G. Kokkinakis, How Conditional Independence Assumption Affects Handwritten Character Segmentation, IAPR, ICDAR’2001, 6th International Conference on Document Analysis and Recognition, pp. 246-250, Sep, 2001, Seattle, Washington, U.S.A
[2]
E. Kavallieratou, D. C. Balcan, M. F. Popa, N. Fakotakis, Handwritten Text Localization in Skewed Documents, ICIP’2001, pp. 1102-1105, 2001
[3]
E. Kavallieratou, N. Liolios, E. Koutsogeorgos, N. Fakotakis, G. Kokkinakis, The GRUHD database of Modern Greek Unconstrained Handwriting, ICDAR’2001, pp. 561-565, 2001
[1]
E. Kavallieratou, N. Liolios, E. Koutsogeorgos, N. Fakotakis, G. Kokkinakis, The GRUHD database of Modern Greek Unconstrained Handwriting, LREC 2000, pp. 1755-1759, 2000
E. Kavallieratou, E. Stamatatos, N. Fakotakis, G. Kokkinakis, Handwritten Character Segmentation Using Transformation-Based Learning, 15th Int. Conf. on Pattern Recognition (ICPR2000), pp. 634-637, 2000
Περίληψη:
This paper presents a character segmentation algorithm for unconstrained cursive handwritten text. The transformation-based learning method and a simplified variation of it are used in order to extract automatically rules that detect the segment boundaries. Comparative experimental results are given for a collection of multi-writer handwritten words. The achieved accuracy in detecting segment boundaries exceeds 82%. Moreover, limited training data can provide very satisfactory results.
This paper presents a character segmentation algorithm for unconstrained cursive handwritten text. The transformation-based learning method and a simplified variation of it are used in order to extract automatically rules that detect the segment boundaries. Comparative experimental results are given for a collection of multi-writer handwritten words. The achieved accuracy in detecting segment boundaries exceeds 82%. Moreover, limited training data can provide very satisfactory results.
[1]
E. Kavallieratou, N. Fakotakis, G. Kokkinakis, New algorithms for skewing correction and slant removal on word-level, ICECS’99, pp. 1159-1162, 1999
[1]
E. Kavallieratou, N. Antoniadis, N. Fakotakis, G. Kokkinakis, Extraction and Recognition of Handwritten Alphanumeric Characters from Application forms, DSP97, pp. 695-698, 1997