Designed By- TEAM EXE

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SAC is basically a utility that accomplishes the task of compressing and splitting up the files. It provides user the option of selecting an algorithm from various algorithms implemented for compressing a file.

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LOSSLESS DATA COMPRESSION Store/transmit large files using few bytes such

that original file can be perfectly retrieved.

SPLITTING FILES Large files can be splitted into various fragments

as specified by the user. A batch file will be generated which when executed will form the original file.

VARIOUS ALGORITHMS IMPLEMENTED Various algorithms for compression have been

implemented . The user can compare and correspondingly employ suitable one.

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PLATFORM INDEPENDENTBuilt in java, SAC can be installed on almost any

hardware platform and operating system.

USER FRIENDLY INTERFACE The interface of the application is built in such a

way that even a layman can understand the functions without any need of help manuals

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Hardware Requirements◦ Processor: Intel Pentium 3 or higher◦ Speed: 1GHz +◦ RAM: 256 MB or Higher◦ Free Disk Space: Minimum 1 MB of free Disk

Space Software Requirements

◦ JDK1.2 (Java Development Kit version 1.2) or higher (depending upon the operating System used)

◦ JRE (Java Runtime Environment) Operating Systemso Windows XP or higher, Linux, Open Solaris, Apple

MAC OS

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Compression: the process of encoding that will effectively reduce the total number of bits needed to represent certain information.

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In Huffman encoding, you assign shorter codes to symbols that occur more frequently and longer codes to those that occur less frequently.

For example:

CharacterCharacter A A B B C C D D E E------------------------------------------------------Frequency 17 12 12 27 32

Frequency of charactersFrequency of characters07/04/23 8

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Final Tree and Codes

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LZW uses fixed-length codewords to represent variable-length strings of symbols/characters that commonly occur together, e.g., words in English text.

LZW places longer and longer repeated entries into a dictionary, and then outputs the code for an element, rather than the string itself, if the element has already been placed in the dictionary.

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String-”how_many_cans_can_a_canner_can”

WORKING :

Dictionary contains the following strings:256 -> ho 263 -> y_ 270 -> _a257 -> ow 264 -> _c 271 -> a_258 -> w_ 265 -> ca 272 -> _can259 -> _m 266 -> ans 273 -> nn260 -> ma 267 -> s_ 274 -> ne261 -> an 268 -> _ca 275 -> er262 -> ny 269 -> an_ 276 -> r_

The compressed output for example looks like this:how_many_c<261>s<264><261>_a<268>nner<272>

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The letters of the input message must be arranged in order from most probable to least probable.

Then the initial set of messages must be divided into two subsets whose total probabilities are as close as possible to being equal. Symbols in the first set receive "0" and symbols in the second set receive "1".

The same process is repeated on those subsets, to

determine successive digits of their codes, as long as any sets with more than one member remain.

When a subset has been reduced to one symbol,

this means the symbol's code is complete.

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Message x1 x2 x3 x4 x5 x6 x7 x8

Probability

0.25 0.25 0.125

0.125

0.0625

0.0625

0.0625

0.0625

x1,x2,x3,x4,x5,x6,x7,x8

x1,x2 x3,x4,x5,x6,x7,x8

x1 x2 x3,x4 x5,x6,x7,x8

x3 x4 x5,x6 x7,x8

0100

1100

100

10

0 1

11

x5 x6 x7 x8

101 110 111

1101 11101111

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Repeated occurrence of the same character is called a run

Number of repetition is called the length of the run

Run of any length is represented by two characters◦ eeeeeeetnnnnnnnn

Coded as-e7t1n8

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File Splitter is a software which is used to split the user specified file.

It provides a solution to the problem of transferring one big file from one end to another through any media like internet or small storage like Floppy, Pen drive etc.

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The fragment size will be provided by the user accordingly the splitted files will be created in the specified destination folder.

After Splitting the file the user is prompted with an option of deleting the original file.

A batch file will be generated which when executed will rejoin the splitted files into the original file.

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Various algorithms mentioned can be further merged to enhance the efficiency of the software.

The splitted files can be executed and run individually , for eg using the software as a video cutter.

Files to be compressed can be picked from various different sources and compressed simultaneously , making the data management quicker and more effective.

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THANK YOU

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