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Compression Methods Based on Context Modelling
Gach, Tomáš ; Drábek, Vladimír (referee) ; Bařina, David (advisor)
The aim of this thesis is to describe basic properties of the context-based compression methods. Modelling procedure is presented together with the principle of an arithmetic coding. Gradually the PPM, CTW, and PAQ methods are introduced together with the possible implementation of the basic PPM probability model. The performance of context-based, dictionary and the most currently used methods of data compression is being compared. Based on obtained results, the possible usage of PPM methods is summarized.
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Implementation of Statistical Compression Method
Šreibr, Jakub ; Polok, Lukáš (referee) ; Bařina, David (advisor)
In this thesis statistical methods for data compression are presented. It deals with projecting of compression process and with it's implementation in a form of program library, which is created in language C++. Description and analysis of compression methods are discussed. The results of tests, which were performed with different compression methods are demonstrated.
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Suffix Graphs and Lossless Data Compression
Senft, Martin ; Dvořák, Tomáš (advisor) ; Dvorský, Jiří (referee) ; Smyth, William F. (referee)
Title: Suffix Graphs and Lossless Data Compression Author: Martin Senft Department: Department of Software and Computer Science Education Supervisor of the doctoral thesis: doc. RNDr. Tomáš Dvorˇák, CSc., Depart- ment of Software and Computer Science Education Abstract: Suffix tree and its variants are widely studied data structures that enable an efficient solution to a number of string problems, but also serve for implementation of data compression algorithms. This work explores the opposite approach: design of compression methods, based entirely on prop- erties of suffix graphs. We describe a unified construction algorithm for suf- fix trie, suffix tree, DAWG and CDAWG, accompanied by analysis of implicit suffix link simulation that yields two practical alternatives. Since the com- pression applications require maintaining text in the sliding window, an in- depth discussionof slidingsuffixgraphsisneeded. Fillinggapsin previously published proofs, we verify that suffix tree is capable of perfect sliding in amortised constant time. On the other hand, we show that this is not the case with CDAWG, thus resolving a problem of Inenaga et al. Building on these investigations,we describea family of data compression methods,based on a description of suffix tree construction for the string to be compressed. While some of...
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Compression Methods Based on Context Modelling
Gach, Tomáš ; Drábek, Vladimír (referee) ; Bařina, David (advisor)
The aim of this thesis is to describe basic properties of the context-based compression methods. Modelling procedure is presented together with the principle of an arithmetic coding. Gradually the PPM, CTW, and PAQ methods are introduced together with the possible implementation of the basic PPM probability model. The performance of context-based, dictionary and the most currently used methods of data compression is being compared. Based on obtained results, the possible usage of PPM methods is summarized.
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Implementation of Statistical Compression Method
Šreibr, Jakub ; Polok, Lukáš (referee) ; Bařina, David (advisor)
In this thesis statistical methods for data compression are presented. It deals with projecting of compression process and with it's implementation in a form of program library, which is created in language C++. Description and analysis of compression methods are discussed. The results of tests, which were performed with different compression methods are demonstrated.
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User friendly cross-platform archivation/dearchivation software
Růžička, Vojtěch ; Pecinovský, Rudolf (advisor) ; Pavlíčková, Jarmila (referee)
An ultimate goal of this bachelor thesis is to create multiplatform software for archiving of data and their effective sharing and handling within a given team frame. The software is based on prior set of requirements. Specific emphasize is paid to the ability of this software to enforce standardization, to allow easy data structure, and to work with large number of data archives. First part contains a compilation of software requirements followed by program proposal which addresses the solution. Based on this analysis particular program is elaborated. The program is available in attachment. The last part is a user's manual.
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