GitHub - arunkthomasuncc/LZWAlgorithm: This repository contains the implementation of LZW Encoder and Decoder compressor algorithm

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This repository contains the implementation of LZW Encoder and Decoder compressor algorithm

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Name		Name	Last commit message	Last commit date
Latest commit History 1 Commit
LZWDecoder.java		LZWDecoder.java
LZWEncoder.java		LZWEncoder.java
README.txt		README.txt
sampleInput.lzw		sampleInput.lzw
sampleInput.txt		sampleInput.txt
sampleInput_decoded.txt		sampleInput_decoded.txt

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Student Details
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ARUN KUNNUMPURAM THOMAS
STUDENT ID :801027386

Programming Language details
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Programming Language: JAVA
Compiler Version : JAVA 8

Instruction to run program
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LZWEncoder
------------
1. Go to project folder from command prompt
2. Execute javac LZWEncoder.java
3. Execute java LZWEncoder <inputfilename with extension><bit length>
ex: java LZWEncoder input1.txt 12
This will create an output file input1.lzw in the same folder
LZWDecoder
------------
1. Go to project folder from command prompt
2. Execute javac LZWDecoder.java
3. Execute java LZWDecoder <outputfile from LZWEncoder><bit length>
ex: java LZWEncoder input1.lzw 12
This will create an output file input1_decoded.txt in the same folder

Program Description and data structure details
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LZWEncoder.java
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It has mainly three operations

1. Reading the input file
2. Encoding
3. Writing to output file

In this program, I am reading the file character by character and passing it to the encoder method. Encoder method is the implementation of LZW compression algorithm. I am using HashMap to represent the
dictionary, so that dictionary search will be fast. Iam writing the encoded codes from encoder to outputfile using UTF-16BE encoding. Program will create a .lzw file with name same as input file in the project directory.

LZWDecoder.java
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It has mainly three operations
1. Reading the input LZW file
2. Decoding
3. Writing the decoded text to output file

In this program, I am reading the LZW file from LZWEncoder using UTF-16BE emcoding and passing the set of integer codes to the decoder method. Decoder method is the implementation of LZW decompression algorithm.
I am using HashMap to represent the dictionary, so that dictionary search will be fast. The program will write the decoded text from decoder to a decoded.txt file. Program will create a file with
name <inputfilename>_decoded.txt file in the project folder.