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prof. dr hab. inż. Andrzej Czyżewski
Employment
- Head of Department at Department of Multimedia Systems
- Professor at Department of Multimedia Systems
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total: 447
Catalog Publications
Year 2013
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Multimodal English corpus for automatic speech recognition
PublicationA multimodal corpus developed for research of speech recognition based on audio-visual data is presented. Besides usual video and sound excerpts, the prepared database contains also thermovision images and depth maps. All streams were recorded simultaneously, therefore the corpus enables to examine the importance of the information provided by different modalities. Based on the recordings, it is also possible to develop a speech...
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Multimodal human-computer interfaces based on advanced video and audio analysis
PublicationMultimodal interfaces development history is reviewed briefly in the introduction. Examples of applications of multimodal interfaces to education software and for the disabled people are presented, including interactive electronic whiteboard based on video image analysis, application for controlling computers with mouth gestures and the audio interface for speech stretching for hearing impaired and stuttering people. The Smart...
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Multimodal Surveillance Based Personal Protection System
PublicationA novel, multimodal approach for automatic detection of abduction of a protected individual, employing dedicated personal protection device and a city monitoring system is proposed and overviewed. The solution is based on combining four modalities (signals coming from: Bluetooth, fixed and PTZ cameras, thermal camera, acoustic sensors). The Bluetooth signal is used continuously to monitor the protected person presence, and in case...
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Novel 5.1 Downmix Algorithm with Improved Dialogue Intelligibility
PublicationA new algorithm for 5.1 to stereo downmix is introduced, which addresses the problem of dialogue intelligibility. The algorithm utilizes proposed signal processing algorithms to enhance the intelligibility of movie dialogues, especially in difficult listening conditions or in compromised speaker setup. To account for the latter, a playback configuration utilizing a portable device, i.e. an ultrabook, is examined. The experiments...
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OCHRONA PRYWATNOŚCI W SYSTEMACH MONITORINGU WIZYJNEGO, PRZEGLĄD OPRACOWANYCH ARCHITEKTUR I ALGORYTMÓW
PublicationNieustannie rozwijające się technologie informacyjne związane z inteligentnym monitoringiem wizyjnym stwarzają ryzyko niewłaściwego wykorzystywania danych osobowych. W celu zapewnienia prawidłowej ochrony materiału wizyjnego, w ramach projektów realizowanych w Katedrze Systemów Multimedialnych WETI PG, opracowany został szereg architektur i algorytmów, które ułatwiają ochronę danych wrażliwych, takich jak: wizerunki osób, numery...
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Online sound restoration system for digital library applications
PublicationAudio signal processing algorithms were introduced to the new online non-commercial service for audio restoration intended to enhance the content of digitized audio repositories. Missing or distorted audio samples are predicted using neural networks and a specific implementation of the Jannsen interpolation method based on the autoregressive model (AR) combined with the iterative restoring of missing signal samples. Since the distortion...
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Online sound restoration system for digital library applications.
PublicationAudio signal processing algorithms were introduced to the new online non-commercial service for audio restoration intended to enhance the content of digitized audio repositories. Missing or distorted audio samples are predicted using neural networks and a specific implementation of the Jannsen interpolation method based on the autoregressive model (AR) combined with the iterative restoring of missing signal samples. Since the distortion...
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Open standards-based communication system for distributed intelligent surveillance solution
PublicationThe paper presents an open standards-based communication system being a part of a distributed surveillance solution. The paradigm of “intelligent” surveillance approach is introduced, and employed video processing is discussed briefly. Requirements analysis toward the design of communication subsystem architecture is presented. Special attention is paid to the multimedia streaming functionality of presented solution, which is based...
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Reversible Video Stream Anonymization for Video Surveillance Systems Based on Pixels Relocation and Watermarking
PublicationA method of reversible video image regions of interest anonymization for applications in video surveillance systems is described. A short introduction to theanonymization procedures is presented together with the explanation of its relation to visual surveillance. A short review of state of the art of sensitive data protection in media is included. An approach to reversible Region of Interest (ROI) hiding in video is presented,...
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Rozpoznawanie osób i zdarzeń: Zakres badań
PublicationRozpoznawanie osób i zdarzeń, analiza strumieni wielomadalnych, cyfrowe przetwarzanie sygnałów.
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Rozpoznawanie ruchów i gestów wykonywanych ustami w obrazie wizyjnym z użyciem sieci neuronowych
PublicationUstomysz jest interfejsem komputerowym, umożliwiającym sterowanie kursorem ekranowym za pomocą ruchów ust i gestów wykonywanych ustami. Główną grupą docelową użytkowników interfejsu są osoby, które z dowolnego powodu nie mogą lub nie chcą posługiwać się tradycyjną klawiaturą i myszką komputerową. W związku z tym, może on umożliwić osobom niepełnosprawnym ruchowo, np. z niedowładem kończyn posługiwanie się komputerem, a przez to...
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Spatial Calibration of a Dual PTZ-Fixed Camera System for Tracking Moving Objects in Video
PublicationA dual camera setup is proposed, consisting of a fixed (stationary) camera and a pan-tilt-zoom (PTZ) camera, employed in an automatic video surveillance system. The PTZ camera is zoomed in on a selected point in the fixed camera view and it may automatically track a moving object. For this purpose, two camera spatial calibration procedures are proposed. The PTZ camera is calibrated in relation to the fixed camera image, using interpolated...
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STEADY STATE VISUALLY EVOKED POTENTIALS FOR BRAIN COMPUTER INTERFACE
PublicationAn experiment conducted to validate a possibility of use a single active electrode EEG device for detecting Steady State Visually Evoked Potentials (SSVEP) is shown. A LED stimulator was applied to stimulate patients with two different frequencies - 13 Hz and 17 Hz. First, EEG signals were recorded and pre-processed using MATLAB software. In the next step recordings were analysed and classified employing the WEKA software. As indicated...
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System komunikacji operacyjnej i dostępu do strumieni multimedialnych dla terminali mobilnych
PublicationPrzedstawiono opracowany system komunikacji multimedialnej zoptymalizowany pod kątem jego wykorzystania w warunkach operacyjnych przez służby odpowiedzialne za ochronę obiektów i bezpieczeństwo. Szczególną uwagę poświęcono funkcjonalności bezprzewodowego dostępu do strumieni multimedialnych pochodzących z kamer systemu „inteligentnego monitoringu”. Przeanalizowano wymagania i omówiono założenia, na których opiera się projekt...
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SYSTEM ZDALNEJ OBSERWACJI AKUSTYCZNO-WIZYJNEJ
PublicationUmożliwia niejawną analizę pola akustycznego dla celów detekcji, klasyfikacji, lokalizacji i jednoczesnego śledzenia ruchu wielu źródeł dźwięku. Składa się z wektorowych czujników akustycznych oraz algorytmów cyfrowego przetwarzania sygnałów. W połączeniu z zestawem kamer umożliwia: nakierowanie kamery obrotowej na wykryte źródło dźwięku, wskazanie źródła dźwięku w obrazie z kamery tradycyjnej lub termowizyjnej, odsłuch dźwięków...
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Śledzenie głowy użytkownika komputera z użyciem kamery Time of Flight
PublicationOpisano opracowaną metodę śledzenia położenia głowy użytkownika komputera lub urządzenia mobilnego przy wykorzystaniu kamery mierzącej czas powrotu wiązki promieniowania elektromagnetycznego podczerwonego odbitej od oświetlanego obiektu (ang. Time Of Flight camera). Dzięki zastosowaniu odpowiednich metod cyfrowego przetwarzania obrazu pozyskanego z kamery tego typu możliwe jest zlokalizowanie użytkownika w przestrzeni 3D. Znajomość...
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Testing Watermark Robustness against Application of Audio Restoration Algorithms
PublicationThe purpose of this study was to test to what extent watermarks embedded in distorted audio signals are immune to audio restoration algorithm performing. Several restoration routines such as noise reduction, spectrum expansion, clipping or clicks reduction were applied in the online website system. The online service was extended with some copyright protection mechanisms proposed by the authors. They contain low-level music features...
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The Application Of A Noise Mapping Tool Deployed In Grid Infrastructure For Creating Noise Maps Of Urban Areas
PublicationThe concept and implementation of the system for creating dynamic noise maps in PL-Grid infrastructure are presented. The methodology of dynamic acoustical maps creating is introduced. The concept of noise mapping, based on noise source and propagation models, was developed and employed in the system. The details of incorporation of the system to the PL-Grid infrastructure are presented. The results of simulations performed by...
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The Innovative Faculty for Innovative Technologies
PublicationA leaflet describing Faculty of Electronics, Telecommunications and Informatics, Gdańsk University of Technology. Multimedia Systems Department described laboratories and prototypes of: Auditory-visual attention stimulator, Automatic video event detection, Object re-identification application for multi-camera surveillance systems, Object Tracking and Automatic Master-Slave PTZ Camera Positioning System, Passive Acoustic Radar,...
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Użyteczność platformy KASKADA (rozdział 6)
PublicationZadania wykonane w ramach projektu MAYDAY EURO 2012 w temacie można podzielić na dwie główne kategorie: prace implementacyjne, obejmujące zarówno implementację rozwiązań ekstrakcji cech twarzy jak i systemów rozpoznawania i typowania osób na platformach WINDOWS i KASKADA, prace badawcze, obejmujące z kolei badania związane ze skutecznością typowania i rozpozna-wania osób oraz możliwości zrównoleglania opracowanych rozwiązań na...
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Video Analytics-Based Algorithm for Monitoring Egress from Buildings
PublicationA concept and practical implementation of the algorithm for detecting of potentially dangerous situations of crowding in passages is presented. An example of such situation is a crush which may be caused by obstructed pedestrian pathway. Surveillance video camera signal analysis performed on line is employed in order to detect hold-ups near bottlenecks like doorways or staircases. The details of implemented algorithm which uses...
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Visual Data Encryption for Privacy Enhancement in Surveillance Systems
PublicationIn this paper a methodology for employing reversible visual encryption of data is proposed. The developed algorithms are focused on privacy enhancement in distributed surveillance architectures. First, motivation of the study performed and a short review of preexisting methods of privacy enhancement are presented. The algorithmic background, system architecture along with a solution for anonymization of sensitive regions of interest...
Year 2012
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A Method of Real-Time Non-uniform Speech Stretching
PublicationDeveloped method of real-time non-uniform speech stretching is presented.The proposed solution is based on the well-known SOLA algorithm(Synchronous Overlap and Add). Non-uniform time-scale modification isachieved by the adjustment of time scaling factor values in accordance with thesignal content. Dependently on the speech unit (vowels/consonants), instantaneousrate of speech (ROS), and speech signal presence, values of the scalingfactor...
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Akustyka
PublicationW artykule przedstawiono zadania realizowane w ramach projektu PL GRID Plus przez zespół wykonawców Katedry Systemów Multimedialnych. Zadanie te obejmują przygotowanie zestawu usług umożliwiających wykonywanie obliczeń map hałasu i wpływu hałasu na słuch z wykorzystaniem infrastruktury PL GRID.
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Analysis of impact of lossy audio compression on the robustness of watermark embedded in the DWT domain for non-blind copyright protection
PublicationA methodology of non-blind watermarking of the audio content is proposed. The outline of audio copyright problem and motivation for practical applications are discussed. The algorithmic theory pertaining watermarking techniques is briefly introduced. The system architecture together with employed workflows for embedding and extracting the watermarks are described. The implemented approach is described and obtained results are reported....
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Application of virtual gate for counting people participating in large public events
PublicationThe concept and practical application of the developed algorithm forpeople counting in crowded scene is presented. The aim of the work is to estimatethe number of people passing towards entrances of a large sport hall. Thedetails of implemented the Virtual Gate algorithm are presented. The video signalfrom the camera installed in the building constituted the input for the algorithm.The most challenging problem was the unpredicted...
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Awareness evaluation of patients in vegetative state employing eye-gaze tracking system
PublicationApplication of eye-gaze tracking system to awareness evaluation is demonstrated. Hitherto awareness evaluation methods are presented. The assumptions of proposed method based on analysis of visual activity of patients in vegetative state are demonstrated. The eye-gaze tracking system ''Cyber-Eye'' developed at the Multimedia Systems Department employed to conducted experiments is presented. Research described in the paper indicates...
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Distributed System For Noise Threat Evaluation Based On Psychoacoustic Measurements
PublicationAn innovative system designed for the continuous monitoring of acoustic climate of urban areas was presentedin the paper. The assessment of environmental threats is performed using online data, acquired through a grid ofengineered monitoring stations collecting comprehensive information about the acoustic climate of urban areas.The grid of proposed devices provides valuable data for the purpose of long and short time acoustic climateanalysis....
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Improved method for real-time speech stretching
Publicationn algorithm for real-time speech stretching is presented. It was designed to modify input signal dependently on its content and on its relation with the historical input data. The proposed algorithm is a combination of speech signal analysis algorithms, i.e. voice, vowels/consonants, stuttering detection and SOLA (Synchronous-Overlap-and-Add) based speech stretching algorithm. This approach enables stretching input speech signal...
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Katedra Systemów Multimedialnych
PublicationThe article provides a historical overview, discuss the issues of teaching and research, and presents the current offer of the Department to industry. This article was written on the occasion of the 60th anniversary of the Faculty of Electronics, Telecommunication and Informatics of Gdansk University of Technology. W artykule zamieszczono rys historyczny, omówienie programu dydaktycznego i tematyki badań naukowych oraz aktualną...
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Methods of Improving Speech Intelligibility for Listeners with Hearing Resolution Deficit
PublicationMethods developed for real-time time scale modification (TSM) of speech signal are presented. They are based onthe non-uniform, speech rate depended SOLA algorithm (Synchronous Overlap and Add). Influence of theproposed method on the intelligibility of speech was investigated for two separate groups of listeners, i.e. hearingimpaired children and elderly listeners. It was shown that for the speech with average rate equal to or...
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New Applications of Multimodal Human-Computer Interfaces
PublicationMultimodal computer interfaces and examples of their applications to education software and for the disabled people are presented. The proposed interfaces include the interactive electronic whiteboard based on video image analysis, application for controlling computers with gestures and the audio interface for speech stretching for hearing impaired and stuttering people. Application of the eye-gaze tracking system to awareness...
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Online Sound Restoration for Digital Library Applications
PublicationA system for sound restoration was conceived and engineered having the following features: no special sound restoration software is needed to perform audio restoration by the user, the process of restoration employs automatic reduction of noise, wow and impulse distortions performed in the online mode, no skills in digital signal processing from the user are needed. The principles of the created system and its features as well...
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Online urban acoustic noise monitoring system
PublicationConcepts and implementation of the Online Urban Noise Monitoring System are presented. Principles of proposed solution used for dynamic acoustical maps creating are discussed. The architecture of the system and the data acquisition scheme are described. The concept of noise mapping, based on noise source model and propagation simulations, was developed and employed in the system. Dynamic estimation of noise source parameters utilized...
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System Supporting Speech Perception in Special Educational Needs Schoolchildren
PublicationThe system supporting speech perception during the classes is presented in the paper. The system is a combination of portable device, which enables real-time speech stretching, with the workstation designed in order to perform hearing tests. System was designed to help children suffering from Central Auditory Processing Disorders.
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Technologia biomems - przegląd zastosowań
PublicationThe paper reviews the issues related to technology, MEMS (Micro-Electro Systems-Mechanical) in the context of applications in biotechnology and biomedical systems. Systems of this type, with applications in biology and medicine, have the name of our common BioMEMS systems. This pertains to a wide range of technology BioMEMS. The aim of this study is to determine future medical MEMS microphones with particular emphasis on their...
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Typoszereg komputerowych interfejsów multimodalnych
PublicationW referacie opisano opracowywane w ramach realizowanego projektu, multimodalne interfejsymultimodalne, ułatwiające użytkowanie urządzeń komputerowych, w tym również terminali mobilnych.Przedstawiono zasady działania poszczególnych interfejsów oraz dotychczasowo uzyskane rezultaty.Wyniki uzyskane zostały drogą prób i eksperymentów z udziałem grup użytkowników docelowych,obejmujących zarówno użytkowników standardowych, jak również...
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Virtual Whiteboard: A gesture-controlled pen-free tool emulating school whiteboard
PublicationIn the paper the so-called Virtual Whiteboard is presented which may be an alternative solution for modern electronic whiteboards based on electronic pens and sensors. The presented tool enables the user to write, draw and handle whiteboard contents using his/her hands only. An additional equipment such as infrared diodes, infrared cameras or cyber gloves is not needed. The user's interaction with the Virtual Whiteboard computer...
Year 2011
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A non-uniform real-time speech time-scale stretching method
PublicationAn algorithm for non-uniform real-time speech stretching is presented. It provides a combination of typical SOLA algorithm (Synchronous Overlap and Add ) with the vowels, consonants and silence detectors. Based on the information about the content and the estimated value of the rate of speech (ROS), the algorithm adapts the scaling factor value. The ability of real-time speech stretching and the resultant quality of voice were...
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An approach to determining tinnitus acoustical characteristic
PublicationFor many treatment methods, accurate estimation of Tinnitus(ringing in ears) concerning sound type, level, and bandwidth or frequency is inevitable. The proposed way of obtaining Tinnitus parameters is described in this paper. The method employs sound synthesis, aimed at obtaining sound which is closest to perceived Tinnitus. The proposed method assumes running a designed application on a multimedia PC provided with a special graphical...
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Application of Vector Sensors to Acoustic Surveillance of a Public Interior Space
PublicationPrzedstawiono metodę precyzyjnej detekcji i lokalizacji źródeł dźwięku w pomieszczeniach. Wykorzystano wektorowe czujniki akustyczne, dostarczające sygnałów ciśnienia akustycznego i prędkości cząsteczek powietrza. Zaprezentowano metodę lokalizacji źródeł dźwięku na widowni wydarzenia publicznego. Przedstawiono demonstracyjny system zainstalowany w sali wykładowej. System poddano ocenie dokładności na podstawie przeprowadzonych...
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Automatic prosodic modification in a Text-To-Speech synthesizer of Polish language
PublicationPrzedstawiono system syntezy mowy polskiej z funkcją automatycznej modyfikacji prozodii wypowiedzi. Opisane zostały metody automatycznego wyznaczania akcentu i intonacji wypowiedzi. Przedstawiono zastosowanie algorytmów przetwarzania sygnału mowy w procesie kształtowania prozodii. Omówiono wpływ zastosowanych modyfikacji na naturalność brzmienia syntezowanego sygnału. Zastosowana metoda oparta jest na algorytmie TD-PSOLA. Opracowany...
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Automatic sound source localization in disturbing conditions using acoustic vector sensors
PublicationA concept, practical realization and applications of a passive acoustic radar to automatic localization and tracking of sound sources in disturbing conditions were presented in the paper. The device consists of the new kind of multichannel miniature sound intensity sensors and a group of digital signal processing algorithms. The sensitivity of the realized acoustic radar was examined in free sound field. Several kinds of sound...
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Badanie rozpoznawania twarzy przez człowieka z wykorzystaniem systemu śledzenia fiksacji wzroku Cyber-Oko
PublicationW celu dokładniejszego zrozumienia sposobu rozpoznawania i zapamiętywania twarzy przez człowieka przeprowadzono doświadczenie na grupie 20 osób z wykorzystaniem wcześniej opracowanego systemu śledzenia fiksacji wzroku Cyber-Oko. Wykorzystując diody i kamerę podczerwieni wraz z dedykowanym oprogramowaniem Cyber-Oko, które pozwala na śledzenie punktu skupienia wzroku na ekranie. Każdej osobie biorącej udział w doświadczeniu pokazano...
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Behavior Analysis and Dynamic Crowd Management in Video Surveillance System
PublicationA concept and practical implementation of a crowd management system which acquires input data by the set of monitoring cameras is presented. Two leading threads are considered. First concerns the crowd behavior analysis. Second thread focuses on detection of a hold-ups in the doorway. The optical flow combined with soft computing methods (neural network) is employed to evaluate the type of crowd behavior, and fuzzy logic aids detection...
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Camera sabotage detection for surveillance systems
PublicationCamera dysfunction detection algorithms and their utilization in realtime video surveillance systems are described. The purpose of using the proposed analysis is explained. Regarding image tampering three algorithms for focus loss, scene obstruction and camera displacement detection are implemented and presented. Features of each module are described and certain scenarios for best performance are depicted. Implemented solutions...
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Communication Platform for Evaluation of Transmitted Speech Quality
PublicationA voice communication system designed and implemented is described. The purpose of the presented platform was to enable a series of experiments related to the quality assessment of algorithms used in the coding and transmitting of speech. The system is equipped with tools for recording signals at each stage of processing, making it possible to subject them to subjective assessments by listening tests or, objective evaluation employing...
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Comparison of various speech time-scale modificartion methods
PublicationThe objective of this work is to investigate the influence of the different time-scale modification (TSM) methods on the quality of the speech stretched up using the designed non-uniform real-time speech time-scale modification algorithm (NU-RTSM). The algorithm provides a combination of the typical TSM algorithm with the vowels, consonants, stutter, transients and silence detectors. Based on the information about the content and...
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Creating Acoustic Maps Employing Supercomputing Cluster
PublicationThe implemented online urban noise pollution monitoring system is presented with regard to its conceptual assumptions and technical realization. A concept of the noise source parameters dynamic assessment is introduced. The idea of noise modeling, based on noise emission characteristics and emission simulations, was developer and practically utilized in the system. Furthermore, the working system architecture and the data acquisition...
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Detection and localization of selected acoustic events in 3D acoustic field for smart surveillance applications
PublicationA method for automatic determination of position of chosen sound events such as speech signals and impulse sounds in 3-dimensional space is presented. The events are localized in the presence of sound reflections employing acoustic vector sensors. Human voice and impulsive sounds are detected using adaptive detectors based on modified peak-valley difference (PVD) parameter and sound pressure level. Localization based on signals...
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