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Effect of Noise on Video Compression
Anton, Matyáš ; Drábek, Vladimír (referee) ; Bařina, David (advisor)
Videos are in fact image signals and as such, they are susceptible to distortions in the form of noise. This thesis' goal was to determine how the presence of noise can affect the results of image data compression as well as what impact might the lossy compression have on the noise present. Four contemporary compression formats were chosen, namely H.264, H.265, Motion JPEG 2000 and DIRAC, representing different approaches to the video compression, especially the contrast between a discrete cosine transform and a discrete wavelet transform.
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Android application for subjective evaluation of video-sequences
Štarha, Dominik ; Přinosil, Jiří (referee) ; Číka, Petr (advisor)
This semestral thesis is focused on a group of four actually used video codecs, namely H.264, HEVC, VP8, VP9. The main objective is to decide on the basis of an evaluation by volunteers which one is the best suitable for video compression. The first part of thesis contains theoretical aspect od the issue. This includes a discussion about the the tested codecs, Android operating system description, performance of the Android Studio software and last but not least, introduction to the assessment methods, used to evaluate video quality, to guarantee the objectivity of the results. The secont part of thesis deals with the implementation of the testing procedure and following evaluation of the data obtained by the assessment.
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Modern video codecs
Bílek, Jan ; Čučka, Milan (referee) ; Číka, Petr (advisor)
This bachelor's thesis focuses on modern video codecs and its output video quality assessment. Firstly, principles of some objective and subjective assessment methods are explained. Afterwards, the most common video codecs are introduced, namely H.264, H.265, VP8, VP9, Dirac~2.2.3, WMV and Sorenson Spark. The outcome of this thesis is a desktop application named VideoCodecs written in C++ language, which uses ffmpeg library for encoding and decoding tasks. As a part of the application, algorithms PSNR, SSIM and M--SVD for objective video quality assessment were implemented. Furthermore, a simulation of transport channel was included, enabling us to bring errors into provided video. Using this application, video quality measurements were carried out, on four test sequences in HD resolution at several bitrates. According to our results, the best video codec regarding the video quality is H.265 before H.264, VP9 and VP8.
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Performance analysis of the newest video encoding standards
Klejmová, Eva ; Polák, Ladislav (referee) ; Slanina, Martin (advisor)
The aim of this work is to describe state-of-the-art high-definition video compression algorithms. The thesis focuses on the differences between algorithms and their functionality. Procedures for video sequences compression based on reference implementations of selected codecs are being proposed and their important parameters are being discussed. Bachelor's thesis deals with comparison of reference implementations based on subjective and objective video quality measurements and time requirements. The graphic interface for selected codecs has been also designed.
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Comparison of compression algorithms for high definition video
Dvořák, Martin ; Polák, Ladislav (referee) ; Slanina, Martin (advisor)
Bachelor's thesis deals with comparison and analysis of various instruments of the present-day compression algorithms used to compress high-definition video. Video sequences require a large amount of memory for their storage and take up bandwidth for their transmission, so it is necessary to compress video signals with regard to the quality of video after decompressing. The work focuses mainly on the differences between the algorithms and overall performance. Part of this work is a compressed video database, comparing the performance of different algorithms and the subjective quality of compressed video.
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Lose video signal compression – quantisation
Balada, Radek ; Kratochvíl, Tomáš (referee) ; Frýza, Tomáš (advisor)
The aim of my bachelor’s thesis is a lose video signal compression. Because sequences of digital video signals typically require vast amount of electronic memory for storage, and occupy much bandwidth during the transmission, the video signals must be compressed. Several video compression standards use two-dimensional discrete cosine transform. My job is to extend one more dimension (time) and make tests of three-dimensional discrete cosine transform. I focused on video quality compared to the compression ratio. This paper also describes a technique for generating the quantisation values for three dimensional discrete cosine transform coefficients.
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