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LPC Speech Coding
Zapletal, Ondřej ; Kyselý, František (referee) ; Rajmic, Pavel (advisor)
The contents of the thesis "LPC speech coding" are studies of this method of a parametric source coding, explanation of mathematical procedures that are used in it (linear prediction, autocorrelation, Levinson-Durbin algorithm, transfer to a form suitable for transmission, Chebyshev root searching polynomial method) and acquaintance with the signification and application of that method in real speech encoders. The task of the original project of this thesis is a description and simulation of a simple speech encoder based on LPC, which transforms a real speech signal into a bit flow, which contains all of the significant parameters for its backward reconstruction (LSF coefficients, pitch period, excitation level, voice detection - AMDF method). One part of this thesis is a discussion about currently used speech encoders.
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Real-Time Wavelet Transform in Pure Data
Zemánek, Karel ; Schimmel, Jiří (referee) ; Rajmic, Pavel (advisor)
The bachelors thesis considers of wavelet transform realization in the real-time in Pure Data. The first part of the thesis is devoted to the theoretical minimum of wavelet transform. The second part is devoted to program Pure Data itself. You can see simply patches and also instruction for external programs compact to PD. The third part is devoted to realization of wavelet transtorm in Pure Data program. It contain specific algorithm for wavelet transform calculation and description of exist program.
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Live typeface
Jiříček, Milan ; Špiřík, Jan (referee) ; Rajmic, Pavel (advisor)
The work describes the theoretical foundations of modern methods of creating new fonts, that is, using information technology, specifically vector programs. It also marginally shows the history of the font, Roman writing, the basic division of its compositions and describes its individual elements. The next part of the project focuses on creating digital fonts and continues with bringing it to live using algorithms and methods that can easily be processed in Matlab programming language. The method of implementation of the bringing the typeface to live is described and presentation of the generated results are then shown in few examples. Attention is also paid to the coordinates system, which is very important to solve geometric transformations, and two-dimensional vector graphics, which are widely used in the design and to render the fonts. Bézier curves and cubic Bézier curves are described in further detail along with vector graphics rasterization. One part of this text describes very important de Casteljau algorithm. The last chapter focuses on implementation in Matlab programming language, the creation of curves, that means single font characters, and the ways of how the algorithm works with transformations. Some sample images showing transformations using different input arguments are displayed in this section as well. There is evaluation of the contribution of this application and the possibilities of further expansion at the end.
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Interactive teaching aids for 3D computer graphics
Balusek, Radim ; Průša, Zdeněk (referee) ; Rajmic, Pavel (advisor)
This diploma thesis deals with the creation of interactive tools for 3D computer graphics. The introduction of the thesis focuses on general theory of curves and surfaces and its mathematical description. The topics of Geometric transformation, Perspective projection and Parametric description of 3-dimensional surface are analysed in more detail. The successive chapter deals with the subject of visualisation of spatial objects in Java platform interface. The practical part describes the implementation of individual applets. JAVA programming language, which uses the library functions JOGL, was employed for the very realization of the interactive tools. The goal of the diploma thesis is the creation of a set of interactive applets in the field of computer graphics. These applets will be placed on the website of the faculty and they will serve students of VUT in Brno to improve the quality of education.
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Directional Image Representations
Zátyik, Ján ; Rajmic, Pavel (referee) ; Průša, Zdeněk (advisor)
Various methods describes an image by specific shapes, which are called basis or frames. With these basis can be transformed the image into a representation by transformation coefficients. The aim is that the image can be described by a small number of coefficients to obtain so-called sparse representation. This feature can be used for example for image compression. But basis are not able to describe all the shapes that may appear in the image. This lack increases the number of transformation coefficients describing the image. The aim of this thesis is to study the general principle of calculating the transformation coefficients and to compare classical methods of image analysis with some of the new methods of image analysis. Compares effectiveness of method for image reconstruction from a limited number of coefficients and a noisy image. Also, compares image interpolation method using characteristics of two different transformations with bicubic transformation. Theoretical part describes the transformation methods. Describes some methods from aspects of multi/resolution, localization in time and frequency domains, redundancy and directionality. Furthermore, gives examples of transformations on a particular image. The practical part of the thesis compares efficiency of the Fourier, Wavelet, Contourlet, Ridgelet, Radon, Wavelet Packet and WaveAtom transform in image recontruction from a limited number of the most significant transformation coefficients. Besides, ability of image denoising using these methods with thresholding techniques applied to transformation coefficients. The last section deals with the interpolation of image interpolation by combining of two methods and compares the results with the classical bicubic interpolation.
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Making OpenType fonts with free software
Bednár, Peter ; Mekyska, Jiří (referee) ; Rajmic, Pavel (advisor)
In thesis themes of typography and computer font of OpenType format is described in details. At the beginning attention is paid to historical development of typeface, where stress is laid mainly on development of Roman and white letter with their characteristics. Having presented basis of typography work is concentrated on topic of digital font with emphasis on possibilities of OpenType format. Further its characteristics and advantages were listed compared to another formats and it was evaluated as format appropriate also for creating font in education process. Letterspacing and kerning were mentioned between basic graphical modifications in creating fonts. In theoretical part of the thesis they were examined in available programs designed for creating font in OpenType format. Except free available means into summary were included also commercial types due to absence of more advanced instruments and functions with free available applications. In evaluation was found that the most convenient for education is Fontlab Fontographer commercial program, free Type lite and Fontforge indicated for Open-source platform. Practical part of the thesis is focused on two chosen programs for creating main font characteristics. The goal was to detect if it is possible to reach identical results when using both programs. Fontographer program enabled to use wide tool palette dedicated to vector graphic processing by means of Adobe Illustrator similar instrument. In the case of Type lite program there were rather less instruments, what is sufficient for elementary work and familiarization with creating of digital typeface. Freeware shortage is basic absence of kerning, spacing or hinting functions. Comparing program possibilities, it falls that freeware programs based on OS Windows with their functionality are sufficient only for entry level users. The best option within free available programs is Fontforge for OS Linux which supports mentioned typographic functions. Fontographer was recommended for teaching of basic characteristics of OpenType font format. Another goal of the thesis was creating of recommended work procedure for creating basic characteristics of OpenType font for students, that is enclosed at the end of the thesis.
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Implementation of BibTeX standard for bibliographic citations using XML
Mazač, Ladislav ; Přinosil, Jiří (referee) ; Rajmic, Pavel (advisor)
This master´s thesis considers implementation of a standard of bibliographic quotation BibTeX using the XML technology. This project starts with theoretical introduction into XML technology problematics. Next part contains introduction into LATEX and its subprogram BibTEX and into its function. Later, the principle of implementation and important parts of XSL transformation (from output les *.bib. *.tex, *.html) source code will be described. Verication of functionality of the implementation is demonstrated using BibTEX database of used literature generated by XML technology.
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Utilizing psychoacoustic model and Wavelet Packet Transform for purposes of audio signal watermarking
Heitel, Tomáš ; Schimmel, Jiří (referee) ; Rajmic, Pavel (advisor)
This Thesis deals with a method to enforce the intellectual property rights and protect digital media from tampering – Digital Audio Watermarking. The main aim of this work is implement an audio watermarking algorithm. The theoretical part defined basic terms, methods and processes, which are used in this area. The practical part shows a process of embedding the digital signature into a host signal and her backward extraction. The embedding rule used spread spectrum technique and a psychoacoustic model. The implemented psychoacoustic model involves two properties of the human auditory system which are frequency masking and representation the frequency scale on limited bands called critical bands. The model is relatively new and based on the DWPT. In terms of above model is then the digital watermark embedded in the wavelet domain. This algorithm is implemented in technical software MATLAB. One part of this work focuses on robustness tests of the algorithm. Common signal processing modifications are applied to the watermarked audio as follows: Cutting of the audio, re-sampling, lossy compression, filtering, equalization, modulation effects, noise addition. The last part of the thesis presents subjective and objective methods usable in order to judge the influence of watermarking embedding on the quality of audio tracks called transparency.
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