function [savings] = wavecompress2(x,mode,outputfile)
%   wavecompress2  - Lossy compression for 2D data 
%
%   [savings] = WAVECOMPRESS2(x,mode,outputfile) compresses the
%   2-D data in x using the mode specified and saves to outputfile.
%   The return value is compression ratio achieved
%
%   The valid values for mode are:
%       1 = high compression, high error
%           (uses bior3.1 filter and 1xE-4 limit)
%       2 = medium compression, medium error
%           (uses bior3.1 filter and 1xE-5 limit)
%       3 = low compression, low error
%           (uses bior5.5 filter and 1xE-7 limit)
%
%   To decompress the data, see: wavedecompress2
%
%   C. Fleizach 16-May-2006
%   cfleizac@cs.ucsd.edu

filter = 'bior5.5';
limit = .0000001;
level = 5;

switch(mode)
    case 1
        filter = 'bior3.1';
        limit = .0001;
        level = 5;
    case 2
        filter = 'bior3.1';
        limit = .00001;
        level = 5;
    case 3
        filter = 'bior5.5';
        limit = .0000001;
        level = 5;
end

[x1,s] = wavedec2(x,level,filter);
s
[x1,numzeros] = stripzeros(x1,limit);
[savings] = compressandsave(x1,s,mode,outputfile,x);

end

function [savings] = compressandsave(x1,s,mode,filename,x)
    newfile = strcat(filename,'.wcm');
    mesg = strcat('Created compressed file: ',newfile);
    mesg
    savefile(x1,s,mode,filename);
    zip(newfile,filename);
    [savings] = compare(newfile,x);
    delete(filename);
end

function [savings] = compare(newfile,x)
    fd1 = fopen(newfile , 'r');
    oldsize = size(x);
    
    [a1] = fread(fd1,inf,'double');
    newsize = size(a1);
    
    savings = (oldsize(1)*oldsize(2)) / newsize(1);
    fclose(fd1);
    
end

function savefile(x1,s,mode,filename)
    fd = fopen(filename , 'wb');
    if fd < 0
        disp(['could not open the frame ' filename]);
    end;

    [n,m] = size(x1);
    fwrite(fd,n,'double');
    fwrite(fd,m,'double');
    fwrite(fd,mode,'double');

    fwrite(fd,s,'double');
    fwrite(fd,x1,'double');
    fclose(fd);

end

function [newA,numzeros] = stripzeros(A,limit)
    s = size(A);
    newA = A;
    numzeros = 0;
    for k=1:s(1)
        for j=1:s(2)      
            if (abs(A(k,j)) < limit)
                numzeros = numzeros + 1;
                newA(k,j) = 0;
            end
        end
    end
end