function I=lifting97(I,s);
len=size(I,1);
for k=1:s
for i=1:len
    [L,H]=lifting_db97(I(i,1:len));
    I(i,1:len/2)=L;
    I(i,len/2+1:len)=H;
end
I(1:len,1:len)=I(1:len,1:len)';
for j=1:len
    [L,H]=lifting_db97(I(j,1:len));
    I(j,1:len/2)=L;
    I(j,len/2+1:len)=H;
end
len=len/2;
end

for i=1:len
    for j=1:len
        if(I(i,j)<0)
            I(i,j)=0;
        end;
        if(I(i,j)>255)
            I(i,j)=255;
        end;
    end
end