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Let the Crowd be Heard - A Crowdsourcing-based Study on Video Coding
Zach, Ondřej
In this paper, we present a crowdsourcing-based study on video codec comparison. We compared the perceived quality of sequences encoded using H.264 and H.265 algorithms. The main advantage of the study is, that the users could watch the videos in their natural environment using their own equipment. The results show, that H.265 may not bring a significantly better quality in SD scenarios, however, in other scenarios, the use of H.265 might be preferred.
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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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Tools for measuring video quality without reference
Zach, Ondřej ; Dostál, Petr (referee) ; Slanina, Martin (advisor)
This diploma thesis deals with objective video quality assessments without reference. Some of the basics of video quality evaluation are described. Also some basic conditions for objective video quality metrics are introduced. The main focus of the thesis are no-reference approaches. Thesis tries to describe basic methods for seeking distortion in video. The difference between spatial-domain oriented and spectral-domain oriented metrics is analyzed. We also describe design of tool for measuring objective video quality in Matlab environment. We then designed and implemented a bit-stream oriented metric for estimation of the PSNR of H.264 coded sequences. Finally, we created a database of video sequences and we held objective tests. Results were compared with results from subjective measurements.
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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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Comparison of Video Codecs
Urbánek, Pavel ; Svoboda, Pavel (referee) ; Bařina, David (advisor)
This thesis is aimed at analysis of video codecs and their comparison. First part of this document provides reader with the basic information on encoding and decoding process including high level description of often used algorithms. It describes codecs and the process of standardization. Second part is focused on test specifications and codecs comparsion itself including conclusion. PSNR, SSim and BD-PSNR are key methods used for comparing codecs.
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Image compression in interactive applications in digital video broadcasting
Bodeček, Kamil ; Vrba, Kamil (advisor)
Compressed images are used very frequently in interactive applications in digital video broadcasting. New methods increasing efficiency of the image transmission in digital video broadcasting networks are proposed. Adaptive spatial filtering methods have been proposed for enhancement of the visual perception of the compressed images. New optimalization method is based on application of the filtering algorithms on more compressed images (data size are reduced). Visual quality enhancement is processed in interactive application. Further, new compression methods JPEG2000 and H.264 for image compression have been analysed. Novel compound image compression method for standard and high spatial television resolution is proposed in the thesis.
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4K real-time video encoding using NVENC technology
Buchta, Martin ; Přinosil, Jiří (referee) ; Kříž, Petr (advisor)
Diploma thesis is focused on real-time 4K video encoding using NVENC technology. First chapter describes the most used video codecs H.264 and HEVC. There is an explanation of the principle of graphic cards and their programmable units. Analysis of the solution of open source Video Codec SDK is also part of the thesis. The main focus of the thesis is an implementation of an application which can handle 4K video encoding from multiple cameras in real time. Performance and qualitative tests were performed for application. Results of these tests were analyzed and discussed.
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Transmitting Streamed Video on Windows Phone
Jež, Adam ; Zachariáš, Michal (referee) ; Herout, Adam (advisor)
The main goal of this bachelor thesis is the design and implementation of an application for mobile system Windows Phone which will be able to broadcast a multimedia stream from the mobile device camera via a packet network. The RTSP protocol is used to establish the connection and to negotiate the transmission conditions. The multimedia data themselves are sent via the RTP protocol. The aforementioned protocols and follow protocols such as RTCP and SDP are described in the thesis. Also the development of the multimedia application for Windows Phone is briefly described. The last part of the thesis deals with the impact of the transportation protocol on the quality of the video. The main result of the thesis is an application almost ready to be published.
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