lsk_main_encode_chen.m

LSK算法源码,欢迎大家交流

function output = LSK_main_encode_chen(x, max_bits, block_size, level)
% Matlab implementation of SPECK 
%
% Encoder
%
% input:    x : input image in wavelet domain
%           max_bits : maximum bits can be used
%           block_size : image size
%           level : wavelet decomposition level
%
% output:   out : bit stream
%
% Initially read image and scan it in MORTON's scan order and use Linear Indexing
%function  [] = encode256()

% The pointers used are
% MS2 - 1, MS4 - 2, MS8 - 3, MS16 - 4, MS32 - 5, MS64 - 6, MS128 - 7, MS256 - 8
% MIP - 0, MSP - 15, MNP - 14, NULL - 13

% Initially read image and scan it in MORTON's scan order and use Linear Indexing
% clear all,clc
clear global
clear mark
global mark

mark(1:block_size*block_size)=13; % Initialize to NULL, Here zero is not considered

map=mapping(block_size);

seqt(map) = x;
% Start Initialization
mn=0;
var=[];

mark = mark_gen(block_size,level);

% for ii=1:64
%     mark(ii)=0; % MIP
% end
% 
% mark(65)=3;mark(129)=3;mark(193)=3;
% mark(257)=4;mark(513)=4;mark(769)=4;
% mark(1025)=5;mark(2049)=5;mark(3073)=5;
% mark(4097)=6;mark(8193)=6;mark(12289)=6;%%%%%%%128*128
% mark(16385) = 7; mark(32769) = 7; mark(49153) = 7;%%256*256
%-----------------------------------------------------------
seqt = double(seqt);
n=fix(log2(max(abs(seqt))));
           % disp('The figure of n is ');disp(n);
n1=n;

output=[];
temp = dec2bin(block_size, 16);output = [ output temp ];
temp = dec2bin(n,8);output = [ output temp ];
temp = dec2bin(level,8); output = [ output temp ];
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   1 : 16 bits for image block size
%   2 : 8 bits for n
%   3 : 8 bits for level
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
bitcnt = 32; cnt_flag = 0;
while n >= 0   %%bitcnt < max_bits   
   ii=1; 
    
    while ii<=block_size*block_size        
        if mark(ii)==0 % i.e., if MIP
            bitcnt = bitcnt + 1;
            if bitcnt > max_bits
                cnt_flag = 1;
                break;
            end;
            if 2^n<=abs(seqt(ii)) & abs(seqt(ii))<2^(n+1)
                output=[output '1'];mn=mn+1;var=[var seqt(ii)];
                mark(ii)=14; % Mark MNP, Newly significant
                
                bitcnt = bitcnt + 1;
                if bitcnt > max_bits
                    cnt_flag = 1;
                    break;
                end;
                if seqt(ii)<0
                    output=[output '1']; % -ve
                else 
                    output=[output '0']; % +ve
                end
            else
                output=[output '0'];
            end
            ii=ii+1;
            
        elseif mark(ii)>0 & mark(ii)<9
            % O/p significance of Marker
            arr=seqt(ii:ii+2^(2*mark(ii))-1); % Check for block significance
            arr=sum([2^n<=abs(arr) & abs(arr)<2^(n+1)]);
            
            bitcnt = bitcnt + 1;
            if bitcnt > max_bits
                cnt_flag = 1;
                break;
            end;            
            
            if arr==0
                output=[output '0'];
                ii=ii+2^(2*mark(ii));
            else
                output=[output '1'];
                partition(ii);
            end
            arr=0;
        else
            ii=ii+1;
        end       
    end 
    
    % REFINEMENT PASS
    
    ii=1;
    while ii<=block_size*block_size
        if mark(ii)==15
            a=dec2bin(abs(seqt(ii)),n1+1);
            
            bitcnt = bitcnt + 1;
            if bitcnt > max_bits
                cnt_flag = 1;
                break;
            end;
            
            output=[output a(n1-n+1)];
            ii=ii+1;
        elseif mark(ii)==14
            mark(ii)=15;
            ii=ii+1;
        else
            ii=ii+2^(2*mark(ii));
        end
    end
    
    % GOTO STEP 2
    if cnt_flag == 1
        break;bitcnt
    end;
    n=n-1;
    %disp('n is');disp(n);
end
 [ mn length(find(abs(seqt)>=2^(n+1))) length(find(mark==15))]
 disp('length of output is');disp(size(output,2));
save filename output
disp(' D O N E ')