rrrr.rar_数字水印源代码_水印

function F = lemwavf(wname) %LEMWAVF Lemarie wavelet filters. % F = LEMWAVF(W) returns the scaling filter % associated with Lemarie wavelet specified % by the string W, where W = 'lemN'. % Possible values for N are: % N = 1, 2, 3, 4 or 5. % N.B: % Using the MATLAB Extended Symbolic Toolbox % possible values of N are positive integers. % M. Misiti, Y. Misiti, G. Oppenheim, J.M. Poggi 12-Mar-96. % Last Revision: 17-Apr-1998. % Copyright 1995-2000 The MathWorks, Inc. % $Revision: 1.10 $ $Date: 2000/06/08 13:43:35 $ if isstr(wname) & ~isempty(wname) lw = length(wname); ab = abs(wname); ii = lw+1; while (47<ab(ii-1)) & (ab(ii-1)<58) , ii = ii-1; end num = wstr2num(wname(ii:lw)); else num = wname; end if isempty(num) | any(num < 1) | any(num ~= fix(num)) error('*** Invalid wavelet number ! ***'); end switch num case 1 F = [... 0.46069299844871 0.53391629051346 0.03930700681965 -0.03391629578182 ... ]; case 2 F = [... 0.31555164655258 0.59149765057882 0.20045477817080 -0.10034811856888 ... -0.01528128420694 0.00846362066021 -0.00072514051618 0.00038684732960 ... ]; case 3 F = [... 0.23108942231941 0.56838231367966 0.33173980738190 -0.09447000132310 ... -0.06203683305244 0.02661631105889 -0.00209952890579 0.00001769381066 ... 0.00128429679795 -0.00053703458679 0.00002283826072 -0.00000928544107 ... ]; case 4 F = [... 0.17565337503255 0.52257484913870 0.42429244721660 -0.04601056550580 ... -0.11292720306517 0.03198741803409 0.00813124691980 -0.00743764392677 ... 0.00548090619143 -0.00140066128481 -0.00054200083128 0.00025607264164 ... -0.00008795126642 0.00003025515674 -0.00000082014466 0.00000027569334 ... ]; case 5 F = [... 0.13807658847623 0.47310642622099 0.48217097800239 0.02112933622031 ... -0.15081998732499 0.01935767268926 0.02716532750995 -0.01588522540421 ... 0.00671209165995 0.00120022744496 -0.00321203819186 0.00115266788547 ... -0.00018266213413 -0.00002953360842 0.00008433396295 -0.00002997969339 ... 0.00000534552866 -0.00000159098026 0.00000003069431 -0.00000000895816 ... ]; otherwise % compute bernstein polynomial of order 4*num-1. % requires the Extended Symbolic Toolbox. if ~exist('maple') msg = '*** The Extended Symbolic Toolbox is required ***'; error(msg) break end order = 4*num-1; mpa('ord',order); maple('readlib(bernstein):'); maple('f:=proc(t) if t<1/4 then 0 else if t >3/4 then 1 else 2*t-1/2 fi fi end:'); cfs = maple('bernstein(ord,f,(1+x)/2);'); ber = sym2poly(cfs); r = roots(ber); v = r-sqrt(r.^2-1); ind = find(abs(v)>1); if ~isempty(ind) v(ind)=ones(size(ind))./v(ind); end F = real(poly(v)); F = F/sum(F); end