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Deriche Edge Detector
Němec, Zbyšek ; Bařina, David (referee) ; Herout, Adam (advisor)
This thesis presents the Deriche edge detector as an interesting alternative to the commonly used edge detectors. The Deriche edge detector's design is presented to the reader as well as its strengths and weaknesses. Performance issues of the Deriche edge detector are described in comparison with the Canny edge detector together with recommendations for using the Deriche detector. Finally, edge detection quality of the Deriche edge detector is compared to the Canny edge detector using robust subjective evaluation method.
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Lossless Video Compression
Kafka, Jan ; Polok, Lukáš (referee) ; Bařina, David (advisor)
This thesis is about the lossless video compression using 3D prediction. At first is introduced the necessary theory about image data modification. This part serves to define important terms, which are needed to start the creative work itself. Then several variants of codec's structure proposals follow, as well as the choice of methods and description of expected characteristics. Here we can get the first idea how the codec works. Then there is a description of some implementation's details, which could give a detailed insight into the codec's inner architecture. In the last part of the work, the implemented codec is tested and its characteristics are compared to another lossless codecs. The result is that the own codec, using the 3D prediction, can defeat all other tested codecs with its compression ratio.
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Wavelet Transform in Image Processing
Dostál, Martin ; Klíma, Ondřej (referee) ; Bařina, David (advisor)
The wavelet transform has been used for several decades and it is still an object of research - especially its recent modifications which are using the so-called second generation wavelets. It has several advantages over other integral transformations. The most important of them are the ability to localize both in time and frequency and an ability to decorrelate some real non-stationary signals such as images. For this reasons, the wavelet transform became an often used tool in many image processing tasks, for example in image compression, edge detection or contrast enhancement. In this thesis, the wavelet transform is explained, including the theoretical foundation and implementation for use with two-dimensional discrete signals. Some of the applications of the wavelet transform are presented and described. The wavelet transform showed to be suitable tool for edge detection, noise reduction, contrast enhancement and HDR compression.
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Lossless Image Compression
Němec, Jaroslav ; Polok, Lukáš (referee) ; Bařina, David (advisor)
This thesis deals with lossless image compression. You can nd all the process of assembling lossless image coder/decoder. There are described many predictors, color models and two entropy coders in this thesis. The results of thesis are compared and disscused with current lossless image format PNG at the end of thesis.
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Comparison of Modern Lossy Image Compression Formats
Kalabza, Marek ; Klíma, Ondřej (referee) ; Bařina, David (advisor)
This thesis compares modern compression methods of digital images on given datasets in terms of quality. First part describes the principle of lossy compression and then compression of JPEG, Lepton, JPEG 2000, JPEG XR, WebP, BPG, HEIF, H.265 intra frame, H.264 intra frame and AV1. Second part focuses on testing, comparison of results and evaluation. It also describes quality metrics (PSNR, PSNR-YUV, SSIM), deals with possible artefacts created during compression and points out the behavior of formats after data corruption. Based on testing and measurement, it was found that the best compression format from the tested lossy image formats is the AV1 format, specifically on the high resolution dataset, the scanned document dataset, and the map dataset.
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Resampling and Correction of Images
Lysáková, Veronika ; Bařina, David (referee) ; Zemčík, Pavel (advisor)
This bachelor thesis is focusing on design and implementation of the application for resampling and correction of image which allows movement of the pixels of a photo and that way to fix small mistakes whilst taking photographs or correct the image. One part of the work describes existing tools for adjustments of photographs and geometric transformations which are being used to make these adjustments.
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Compression Methods Based on Context Modelling
Kozák, Filip ; Drábek, Vladimír (referee) ; Bařina, David (advisor)
Purpose of this thesis is to describe the context-based compression methods and their application to multimedia data. There is described the principle of arithmetic coding and prediction by partial matching method, including creation of the probability model. There are also described multimedia data and the basic principles of their compression. The next section presents compression methods, that I implemented at work and their results.
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Motion-Blurred Image Restoration
Rajnoch, Zdeněk ; Seeman, Michal (referee) ; Bařina, David (advisor)
Goal of this thesis is restauration of motion blurred images. Motion blurr is assumed to be only over a narrow line rotated by any angle to x axis. There are several methods which are theoretically explained and compared on synthetically blurred images in several different conditions. After that motion blurred images are restaurated with some of deconvolution methods.
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Lifting Scheme Cores for Wavelet Transform
Bařina, David ; Kälviäinen, Heikki (referee) ; Sojka, Eduard (referee) ; Zemčík, Pavel (advisor)
Práce se zaměřuje na efektivní výpočet dvourozměrné diskrétní vlnkové transformace. Současné metody jsou v práci rozšířeny v několika směrech a to tak, aby spočetly tuto transformaci v jediném průchodu, a to případně víceúrovňově, použitím kompaktního jádra. Tohle jádro dále může být vhodně přeorganizováno za účelem minimalizace užití některých prostředků. Představený přístup krásně zapadá do běžně používaných rozšíření SIMD, využívá hierarchii cache pamětí moderních procesorů a je vhodný k paralelnímu výpočtu. Prezentovaný přístup je nakonec začleněn do kompresního řetězce formátu JPEG 2000, ve kterém se ukázal být zásadně rychlejší než široce používané implementace.
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Audio and/or Video for Showroom
Bukovinský, Denis ; Bařina, David (referee) ; Zemčík, Pavel (advisor)
The main goal of this work was to design and implement a system for video distribution in exhibition rooms. The work describes and analyzes existing technologies and products. After performing the analysis, a technical solution was proposed, which was subsequently implemented. The implemented system consists of a web server and a user interface. The result of this work is fully usable for video distribution in presentation rooms.
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