KELOMPOK 12_Kompresi BWT

8/2/2019 KELOMPOK 12_Kompresi BWT

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KELOMPOK 12

Tugas Kompresi Menggunakan Metode Burrows Wheeler

Transform (BWT) Menggunakan MatLab

Disusun oleh :

Nur Agisna Eka Sukmadiyana (109091000026)

Miftakhul Hasan (109091000133)

Kelas: TI 6A Multimedia

PROGRAM STUDI TEKNIK INFORMATIKA

FAKULTAS SAINS DAN TEKNOLOGI

UIN SYARIF HIDAYATULLAH JAKARTA

2012


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Kompresi menggunakan metode Burrows Wheeler

Source :clear all;clc;file_open=fopen('test.txt','r');

file_read=fread(file_open,'uint8');fclose(file_open);a=file_read;b=zeros(1,2*length(a));

for sort_len=1:length(b)if(sort_len>length(a))b(sort_len)=a(sort_len-length(a));

elseb(sort_len)=a(sort_len);

endenda=char(a);

b=char(b);to_sort=zeros(length(a),length(a));for row_sort=1:length(a)

to_sort(row_sort,:)=b(row_sort:length(a)+row_sort-1);endchar(to_sort);[lexi_sorted_data,ind]=sortrows(to_sort);char(lexi_sorted_data);

encoded_data=lexi_sorted_data(:,length(a));primary_index=find(ind==2);out_data=[encoded_data',primary_index];file_bwt=fopen('bwt.cmp','w');fwrite(file_bwt,out_data,'uint8');fclose(file_bwt);

%%%%%%%%%%%%%%%%BWT DECODING STARTSdec_bwt_file=fopen('bwt.cmp','r');dec_bwt_read=fread(dec_bwt_file,'uint8');fclose(dec_bwt_file);

encoded_data=dec_bwt_read(1:length(dec_bwt_read)-1);primary_index=dec_bwt_read(length(dec_bwt_read));

sorted_data=sort(encoded_data);

vector_flag=ones(1,length(encoded_data))';vector=zeros(1,length(encoded_data))';%%%%%%%preparing vector tablefor i=1:length(sorted_data)

for j=1:length(sorted_data)if(encoded_data(j)==sorted_data(i) && vector_flag(j))

% clc;% encoded_data(j);% sorted_data(i);

vector_flag(j);


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vector(i)=j;vector_flag(j)=0;break

endend

end

index=primary_index;reconst_data=zeros(1,length(encoded_data));%getting original data backfor i=1:length(encoded_data)

reconst_data(i)=encoded_data(index);index=vector(index);

end

char(lexi_sorted_data(:,length(a)))primary_index=find(ind==2)

char(reconst_data)


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Hasil Terjemahan Kompresi

ans =


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ans =

MA Imran Akthar

[email protected]

>>

PrintScreen :


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Program BWT Decoder

function bwtdec%bwtdec is a BWT decoder% type bwtdec at the command prompt% this particular function reads the transformed(BWT)% file bwt.txt and then geets the original file back% as orig_text% BE SURE that the transformed file BWT.TXT is in the% current directory%copyright


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%MA Imran [email protected]%please send me ur feedback and suggestion%do check out my other files at MATLAB CENTRAL FILE EXCHANGE

%http://www.mathworks.com/matlabcentral/fileexchange/loadAuthor.do?objectType=author&objectId=1093740

clear all;clc;dec_bwt_file=fopen('bwt.cmp','r');dec_bwt_read=fread(dec_bwt_file,'uint8');fclose(dec_bwt_file);disp('BWT DECODING Started');

encoded_data=dec_bwt_read(1:length(dec_bwt_read)-1);primary_index=dec_bwt_read(length(dec_bwt_read));

sorted_data=sort(encoded_data);vector_flag=ones(1,length(encoded_data))';

vector=zeros(1,length(encoded_data))';%%%%%%%preparing vector tablefor i=1:length(sorted_data)

for j=1:length(sorted_data)if(encoded_data(j)==sorted_data(i) && vector_flag(j))

% clc;% encoded_data(j);% sorted_data(i);

vector_flag(j);vector(i)=j;vector_flag(j)=0;break

endend

end

index=primary_index;reconst_data=zeros(1,length(encoded_data));%getting original data backfor i=1:length(encoded_data)

reconst_data(i)=encoded_data(index);index=vector(index);

end

% char(lexi_sorted_data(:,length(a)));% primary_index=find(ind==2);

% char(reconst_data);

rec_file=fopen('orig_file.txt','w');fwrite(rec_file,reconst_data,'uint8');fclose(rec_file);disp('BWT Decosing over..');disp('file writeen back as orig_file.txt')


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Hasil Decoder :


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Program BWT Encoder

Source :function bwtenc%bwtenc is a BWT encoder% type bwtenc at the command prompt and

% a user interface is dispalyed.% currently,its just text file.u can select just text files% for now.%the BWT transformed file is written as bwt.cmp in the%current directory%copyright%MA Imran [email protected]%please send me ur feedback and suggestion%do check out my other files at MATLAB CENTRAL FILE EXCHANGE


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%http://www.mathworks.com/matlabcentral/fileexchange/loadAuthor.do?objectType=author&objectId=1093740

clear all;

clc;path=pwd;[filename, pathname] = uigetfile('*.txt', 'Pick a file');cd(pathname)file_open=fopen(filename,'r');file_read=fread(file_open,'uint8');fclose(file_open);cd(path)disp('precessing..BWT Transform');a=file_read;b=zeros(1,2*length(a));

for sort_len=1:length(b)

if(sort_len>length(a))b(sort_len)=a(sort_len-length(a));else

b(sort_len)=a(sort_len);endenda=char(a);b=char(b);to_sort=zeros(length(a),length(a));for row_sort=1:length(a)

to_sort(row_sort,:)=b(row_sort:length(a)+row_sort-1);endchar(to_sort);[lexi_sorted_data,ind]=sortrows(to_sort);char(lexi_sorted_data);

encoded_data=lexi_sorted_data(:,length(a));primary_index=find(ind==2);out_data=[encoded_data',primary_index];file_bwt=fopen('bwt.cmp','w');fwrite(file_bwt,out_data,'uint8');fclose(file_bwt);disp('BWT Transform over');disp('file written to bwt.cmp');


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Hasil Encoder :


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KELOMPOK 12_Kompresi BWT

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