Data Compression and Decompression Algorithms
Table of Contents
Introduction………………………………………………………………………..…………………………….…2
1.Data Compression……………………………………..………………………………………………………2 1.1Classification of Compression……………………………………………………………………...2 1.2 Data Compression methods…………………………………………..……………………………3
2. Lossless Compression Algorithm……………..……………………………………………………….4 2.1 Run-Length Encoding……………………..…………………………….……………………………4 2.1.1 Algorithm……………………………..………………………………………………………………….5 2.1.2Complexity ……………………………..………………………………..……………………………….5 2.1.3 Advantages and disadvantage…………..…………………….………………………………6
3. Huffmann coding………………………………..……………………….…………………………………6 3.1 Huffmann encoding…………………………..………………………………………………………..6 3.2 Algorithm…………………………………………………………..……………………………………….7
4. Lempel-Ziv algorithm…………………………………………..……………………………………………7 4.1 Lempel-Ziv78……………………………………………..……………………………………………….8 4.2Encoding Algorithm……………………………………………………………………………………..8 4.3 Decoding Algorithm…………………………………………………………………………………..12
5.Lempel-Ziv Welch…………………………………………………………………………………………….14 5.1 Encoding Algorithm…………………………………………………………………………………..14 5.2 Decoding Algorithm…………………………………………………………………………………..16
References………………………………………………………………………………………………………….17
INTRODUCTION:
Data compression is a common requirement for most of the computerized applications. There are number of data compression algorithms, which are dedicated to compress different data formats. Even for a single data type there are number of different compression algorithms, which use different approaches. This paper examines lossless data compression algorithms.
1. DATA COMPRESSION:
In computer science data compression involves encoding information using fewer bits than the original representation.Compression is useful because it helps reduce the consumption of resources such as data space or transmission capacity. Because compressed data must be decompressed to be used, this extra processing imposes computational or
Introduction………………………………………………………………………..…………………………….…2
1.Data Compression……………………………………..………………………………………………………2 1.1Classification of Compression……………………………………………………………………...2 1.2 Data Compression methods…………………………………………..……………………………3
2. Lossless Compression Algorithm……………..……………………………………………………….4 2.1 Run-Length Encoding……………………..…………………………….……………………………4 2.1.1 Algorithm……………………………..………………………………………………………………….5 2.1.2Complexity ……………………………..………………………………..……………………………….5 2.1.3 Advantages and disadvantage…………..…………………….………………………………6
3. Huffmann coding………………………………..……………………….…………………………………6 3.1 Huffmann encoding…………………………..………………………………………………………..6 3.2 Algorithm…………………………………………………………..……………………………………….7
4. Lempel-Ziv algorithm…………………………………………..……………………………………………7 4.1 Lempel-Ziv78……………………………………………..……………………………………………….8 4.2Encoding Algorithm……………………………………………………………………………………..8 4.3 Decoding Algorithm…………………………………………………………………………………..12
5.Lempel-Ziv Welch…………………………………………………………………………………………….14 5.1 Encoding Algorithm…………………………………………………………………………………..14 5.2 Decoding Algorithm…………………………………………………………………………………..16
References………………………………………………………………………………………………………….17
INTRODUCTION:
Data compression is a common requirement for most of the computerized applications. There are number of data compression algorithms, which are dedicated to compress different data formats. Even for a single data type there are number of different compression algorithms, which use different approaches. This paper examines lossless data compression algorithms.
1. DATA COMPRESSION:
In computer science data compression involves encoding information using fewer bits than the original representation.Compression is useful because it helps reduce the consumption of resources such as data space or transmission capacity. Because compressed data must be decompressed to be used, this extra processing imposes computational or
References: * http://www.sqa.org.uk/e-learning/BitVect01CD/page_86.htm * http://www.gukewen.sdu.edu.cn/panrj/courses/mm08.pdf * http://www.cs.cmu.edu/~guyb/realworld/compression.pdf * http://www.stoimen.com/blog/2012/01/09/computer-algorithms-data-compression-with-run-length-encoding/ * http://www.ics.uci.edu/~dan/pubs/DC-Sec1.html#Sec_1 * http://www.prepressure.com/library/compression_algorithms/flatedeflate * http://en.wikipedia.org/wiki/Data_compression * http://www.google.com.pk/#hl=en&q=lempel+ziv+algorithm+ppt&oq=lempel+ziv+algorithm+ppt&aq=f&aqi=g1&aql=&gs_l=serp.3..0.11251.12329.4.12548.4.3.0.1.1.0.422.422.4-1.1.0...0.0.qB5HdetQcjU&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=1de8caf326efdf37&biw=1024&bih=535 * http://www.cs.cmu.edu/~guyb/realworld/compress.html * http://www.ccs.neu.edu/home/jnl22/oldsite/cshonor/jeff.html