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Development of IP Multimedia Subsystem architecture
Hladíková, Vladimíra ; Číka, Petr (referee) ; Novotný, Vít (advisor)
Bachelor thesis topic is focused on convergence of networks and services in the environment of mobile networks with implementation of Internet Protocol Multimedia Subsystem (IMS). The first part is, devoted to reasons of design of new system, such as IMS (Internet Protocol Multimedia Subsystem) and which possibilities this architecture brings to users. I mentioned institutions and organizations, which are involved in the development of this system. In this chapter is shortly defined history of single standardised parts. In the next part is defined the IMS architecture its main part and functions. I defined which services of this system are possible to offer. To guarantee the high-quality transfer in the sites based on IP protocol is very important to guarantee quality of QoS (Quality of Service) services. So I take the aim to that in one of the next chapters. I mentioned quality assurance principles. The main factor that influences the quality of the transfer is which type of data is being transferred in IP network. The next charter is devoted authentication and authorisation in IMS network. I described the integration with Diameter protocol. The main part is devoted to VoIP (Voice over IP), the transfer of voice in IP networks. I defined the main idea of transfer of voice in IP networks. Codecs are very important for the voice transfer in IP networks, so I give a conspectus here. The next chapter gives attention to used protocols. The system could not work without them. It goes around SDP (Session Description Protocol), protocols for real-time data transfer RTP (Real-time Transport Protocol), RTCP (RTP Control Protocol), RTSP (Real-Time Streaming Protocol) - and the most important signalling protocol SIP (Session Initiation Protocol) and its integration with IMS. Finally I rated possibilities of IMS in mobile communication network and their use for VoIP. Among others I take into consideration also economical influences over the expansion of equipment supporting services with implementation IMS for general public.
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Video compression based on wavelet transform
Kintl, Vojtěch ; Číka, Petr (referee) ; Malý, Jan (advisor)
This diploma thesis focuses on current possibilities concerning the employment of wavelet transformation for video signal compression. One part of the work is devoted to the necessary execution of this task in practise. This deals with video signal and its features description, wavelet transformation and compression methods. The second part concentrates on description of selected compression method. It is the SPIHT (Set Partitioning In Hierarchical Trees) algorithm which is intended for compression of static image data. The algorithm is modified for usage with video signal compression which is specific for its time redundancy. The algorithm is called 3D SPIHT as it works in the spatial and time domain. The algorithm is implemented in the MATLAB programming environment which provides a sophisticated support for wavelet transformation (Wavelet Toolbox). To provide a simple and intuitive encoder control there has been developed an application delivering graphical user interface (GUI). On displayed image previews and measured graphs the user can change encoder parameters and monitor performed changes. There are four image test-sequential modes containing various scenes with different features. The final part of the work is focused on testing of the proposed encoding scheme, various image test-sequential modes and encoder settings. Measured values are graphically displayed and analyzed.
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Digital Library
Krbeček, Daniel ; Přinosil, Jiří (referee) ; Číka, Petr (advisor)
The thesis contains basic information about image documents digitalization. A brief list of common used standards in Czech republic is shown. The standards can be used in description of digitalized documents by institutions such as libraries, scientific departments and universities. The thesis specifically solves the dilemma of the preservation and the accessing of B.P.Molls large map collection stored in Moravian Library in Brno city. It analyses step by step the characteristics of the saved documents, style of their interlacing and data representation. In terms of deposition and manipulation it comes with description list of open-source digital libraries and it chooses the Fedora repository. It solves methods of object-model implementation while using this digital library. The functional parts are web presentation of the mentioned map collection and an effectiveness test showing large-scale maps using the flash Zoomify browser. Web presentation uses the repository services as often as possible, and thus allows searching and searching through the bibliographic records of the presented documents. The end of the thesis sums up the obtained results and presents the incoming development course of presentation and popularization of the map collection.
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Face recognition
Škrobák, Dalibor ; Číka, Petr (referee) ; Kyselý, František (advisor)
This thesis is focused on face detection in static picture. Theoretical part contains color spaces (RGB, HSI, YCbCr), methods for skin detection (explicit, parametric or non-parametric methods), image metric, edge detection, mathematical morphology, methods for classification faces (appearance-based methods, feature invariant approaches, knowledge-based methods, template matching methods). Practical part of this thesis contains concept and practical realization two algorithms for segmentation skin in static image (simple method based on Cr chroma components and statistical method). Practical part contains concept and practical realization two algorithms for classification face (appearance-based method and template matching method) too.
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Human body detection in a video scene
Šmirg, Ondřej ; Číka, Petr (referee) ; Kohoutek, Michal (advisor)
The project consists of two distinct levels i.e. separation level and diagnostic level. At the separation level, statistical models of gaussians and color are separately used to classify each pixel as belonging to backgroung or foreground. Adopted method is mixture of gaussians.A mixture of gaussians model is suitable here because the results of the picture tests will not depend on the lens opening, but rather on the colors in the backgroung. A mixture of gaussians model for return data seems reasonable. The achieved results the used method on the real sequences are presented in the thesis. Diagnostic level is identified human body on the scene. Adopted method is ASM(Active Shape Models) with PCA(Principal Component Analysis). ASM are statistical models of the shape of human bodies which iteratively deform to fit to an example of the object in a new image.
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Watermarking of digital data
Kupka, Jan ; Přinosil, Jiří (referee) ; Číka, Petr (advisor)
The main aim of this project is to implement two different types of the watermarking algorithm in frequency (transforamtion) domain. Because of the huge amount of the watermarking algorithms is this thesis dedicated to the watermarking methods in the frequency domain. These methods use kind of transformation implemented on the original data, the second step is modification of transformation coeficients. This project is dedicated to the methods which use discrete wavelet transformation. Nowdays the most popular transformation, which meets the best efforts. The aim of every method is to embeed the watermark into the original data so precisly, that none observer can recognize any change between the original and watermarked data. On the contrary, watermarked picture should be as resistant to the attacks as possible. By the term of attack, we understand all the ways, that disable watermark extraction. The watermark method robustness will be tested with the use of Checkmark program.
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Methods for image enhancement in interactive applications of digital telecasting
Švanda, Vít ; Vlach, Jan (referee) ; Číka, Petr (advisor)
In this dissertation we deal with methods of minimizing block artefacts in digital terrestrial TV broadcasting. These artefacts are caused by compressions based on the cosine transformation (JPEG, MPEG2 I-Frames). The aim of this work is therefore to create a DVB-J application the main function of which would be to minimize block artefacts in natural images transmitted by DVB-T. That is why we first inquire into the technology of DVB digital transmission and MHP platform which provides the function and the running of interactive applications. Next, we define differences between Java and JavaTV languages and describe the way they develop, simulate and start DVB-J applications. In the following part of this work, we analyze methods that can be used to detect and minimize block artefacts. Further on, we describe the design of an adaptive filter which minimizes block artefacts (hereinafter just ´MHP-MBA´). The major result of the entire work is an MHP-Deblocking application that in itself implements a newly created MHP-MBA deblocking filter as well as a filter from video kodek H.263. In the final part we concern ourselves with testing this application on a genuine set-top-box in DVB-T broadcasting.
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MHP application
Holík, Tomáš ; Říha, Kamil (referee) ; Číka, Petr (advisor)
This Master Thesis is engaged in designing an interactive application for online betting in the DVB-T environment. The application is determined to running at Multimedia Home Plattform MHP and it allowes digital television viewers to make a bet on a sport match broadcasted on the television. The whole application is written in the Java language. All the information about users and the match are stored in a MySQL database, which is accessible through a php script placed on the server with the database. The applicaton is running in a set-top box and communicates with the script through the set-top box return channel. The channel between the server and the script is unsecure, so the communication has to be encrypted. The encryption process uses a symmetric-key cipher AES, which uses a shared secret key for encryption and decryption. Each application generates its own pseuodorandom and crypthographicaly strong AES key and sends it to the server. To secure the secret key transsmision is used the public-key cipher RSA.
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Management and configuration of Asterisk VoIP exchange
Binder, Tomáš ; Krajsa, Ondřej (referee) ; Číka, Petr (advisor)
This diploma dissertation is dealing with the VoIP software exchange Asterisk. In the dissertation there are described its abilities and possible ways of its configuration. Special attention is given to the signalling protocol SIP, which is described in one of the chapters. Within this dissertation a dial plan, which demonstrates the technique of dial plan creating, was created. Within the boundaries of the dialplan following services could be found: a voicemail, conference, Interactive Voice Response and call queues. Configuration files, with the help of which the exchange is configurated, are described in my dissertation as well. Finally, three laboratory assignments for purposes of the subject Multimedia Services are mentioned. Their main aim is to familiarise students with the creation of SIP accounts in the exchange, their mutual connections, defining the Interactive Voice Response and forming a new call centre.
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Watermarking of static images
Bambuch, Petr ; Burda, Karel (referee) ; Číka, Petr (advisor)
The thesis deals with the security of static images. The main aim is to embed the watermark into the original data so effectively, to avoid removal of the watermark with the use of simple and fast attacks methods. With developing of the watermarking techniques the technique of attacks are improved and developed also. The main aim of the attacks is to remove and devalue the hidden watermark in the image. The goal of the thesis is to check current techniques of static image watermarking and implement two methods of watermarking, which are to be tested for robustness against attacks.
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