|
|
Videocodec - Videosequence Compression
Bařina, David ; Motlíček, Petr (referee) ; Smrž, Pavel (advisor)
This thesis deals with modern methods of a lossy still image and video compression. Wavelet transformation and SPIHT algorithm also belong to these methods. In second half of this thesis, a videocodec is implemented based on acquired knowledge. This codec uses Daubechies wavelets to analyse an image. Afterwards there is a modified SPIHT algorithm applied on gained coefficients. A lot of effort was put in order to optimize this computation. It is possible to use the created codec in Video for Windows, DirectShow and FFmpeg multimedia frameworks. At the end of this thesis, commonly used codecs are compared with newly created one.
|
|
|
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.
|
|
|
ECG signals compression
Botlová, Simona ; Vítek, Martin (referee) ; Smital, Lukáš (advisor)
This bachelor thesis deals with the compression of ECG signals using wavelet transform and run length encoding. The principles of electrocardiography, compression methods, wavelet transform and run length encoding are described in this thesis. There was created a program to compress and decompress ECG signals in MATLAB interface. The wavelet transform settings and their influence on compress ratio and percentage root mean square difference were tested. Subsequently, the appropriate adjustment of algoritm was found and it was used on CSE database compression.
|
|
|
Digital Audio Effects Based on the Wavelet Transform
Friedberg, Jiří ; Zezula, Radek (referee) ; Rajmic, Pavel (advisor)
The object of this bachelor thesis is knowing with possibilites of using wavelet transform and thresholding for project of digital audio effects. There are explain basics of wavelet transform and thresholding. This work also include description of project of fifthteen digital audio effects. Ten of them is programmed in Matlab with using GUIDE and inclose to this bachelor thesis to check out.
|
|
|
ECG Signal Compression Based on Wavelet Transform
Ondra, Josef ; Hrubeš, Jan (referee) ; Kozumplík, Jiří (advisor)
Signal compression is daily-used tool for memory capacities reduction and for fast data communication. Methods based on wavelet transform seem to be very effective nowadays. Signal decomposition with a suitable bank filters following with coefficients quantization represents one of the available technique. After packing quantized coefficients into one sequence, run length coding together with Huffman coding are implemented. This thesis focuses on compression effectiveness for the different wavelet transform and quantization settings.
|
|
|
Image codecs based on the wavelet transform
Kiska, Tomáš ; Říha, Kamil (referee) ; Rajmic, Pavel (advisor)
This bachelor´s thesis describes issues of wavelet compression, which is today already in common use mainly at work with digital photographs or other pictures. Using these algorithm you can copy informations and save efficiently. There are main image formats and types of compression suitable for editing pictures desribed in this thesis. So the focus is on discrete wavelet transform, which uses so-called wavelets, the Haar´s and Daubechies wavelet are the best known of all. Next chapter of this work explores colour spaces, in which can be a picture displayed. In case of coding and encoding it is model RGB and YCbCr. Not least there is mentioned term of picture decomposition. At the end, there are image codecs EZW, SPITH and EBCOT which are describe in detail.
|
|
|
Image Compression Using the Wavelet Transform
Kontra, Matúš ; Drábek, Vladimír (referee) ; Bařina, David (advisor)
Wavelet transform belongs to modern methods used to compress data. It's application modifies data in such way, that we can use and store them in much more efficient way. Focus of this thesis lies in theoretical basis required to understand this method and its implementation. Next section shifts focus to quantization and coding - operations used to further reduce size of our data, which are provided by the SPIHT algorithm.
|
|
|
Image Compression Using the Wavelet Transform
Urbánek, Pavel ; Polok, Lukáš (referee) ; Bařina, David (advisor)
This thesis is focused on subject of image compression using wavelet transform. The first part of this document provides reader with information about image compression, presents well known contemporary algorithms and looks into details of wavelet compression and following encoding schemes. Both JPEG and JPEG 2000 standards are introduced. Second part of this document analyzes and describes implementation of image compression tool including inovations and optimalizations. The third part is dedicated to comparison and evaluation of achievements.
|
|
|
Time-Frequency Signal Analysis
Kubala, Matej ; Polok, Lukáš (referee) ; Bařina, David (advisor)
This bachelor thesis is dealing with explanation of time-frequency signal analysis. Basic definitions and terms of signal processing and spectral analysis will be explained, especially focused on transfer time domain into freqency and inverse. The main objective of thesis is to explain in detail and compare two of the most popular methods, Fourier transform and Wavelet transform. Results will be illustrated on implemented application, which loads sound record and computes frequency in specific time using these methods.
|
|
|
JPEG 2000 Implementation
Zlatohlávek, Adam ; Klíma, Ondřej (referee) ; Bařina, David (advisor)
The aim of this thesis is to propose a image compression methods in JPEG 2000. This consists of description of techniques used in base level stadard and analyze options in encoding process. The goal is to create compression process of input image from preprocessing to own output format. In the end of paperwork are presented results of own implementation in memory consuptions and encoding performance.
|
guest ::
