rice-大学小波分析包-daubcqf

function[h_0,h_1]=daubcqf(N,TYPE)

%[h_0,h_1]=daubcqf(N,TYPE);

%

%FunctioncomputestheDaubechies'scalingandwaveletfilters

%(normalizedtosqrt(2)).

%

%Input:

%N:Lengthoffilter(mustbeeven)

%TYPE:Optionalparameterthatdistinguishestheminimumphase,

%maximumphaseandmid-phasesolutions('min','max',or

%'mid').Ifnoargumentisspecified,theminimumphase

%solutionisused.

%

%Output:

%h_0:MinimalphaseDaubechies'scalingfilter

%h_1:MinimalphaseDaubechies'waveletfilter

%

%Example:

%N=4;

%TYPE='min';

%[h_0,h_1]=daubcqf(N,TYPE)

%h_0=0.48300.83650.2241-0.1294

%h_1=0.12940.2241-0.83650.4830

%

%Reference:"OrthonormalBasesofCompactlySupportedWavelets",

%CPAM,Oct.89

%

%FileName:daubcqf.m

%LastModificationDate:01/02/96 15:12:57

%CurrentVersion:daubcqf.m 2.4

%FileCreationDate:10/10/88

%Author:RameshGopinath<ramesh@>

%

%Copyright(c)2000RICEUNIVERSITY.Allrightsreserved.

%CreatedbyRameshGopinath,DepartmentofECE,RiceUniversity.

%

%Thissoftwareisdistributedandlicensedtoyouonanon-exclusive

%basis,free-of-charge.Redistributionanduseinsourceandbinaryforms,

%withorwithoutmodification,arepermittedprovidedthatthefollowing

%conditionsaremet:

%

%1.Redistributionofsourcecodemustretaintheabovecopyrightnotice,

%thislistofconditionsandthefollowingdisclaimer.

%2.Redistributioninbinaryformmustreproducetheabovecopyrightnotice,

%thislistofconditionsandthefollowingdisclaimerinthe

%documentationand/orothermaterialsprovidedwiththedistribution.

%3.Alladvertisingmaterialsmentioningfeaturesoruseofthissoftware

%mustdisplaythefollowingacknowledgment:Thisproductincludes

%softwaredevelopedbyRiceUniversity,Houston,Texasanditscontributors.

%4.NeitherthenameoftheUniversitynorthenamesofitscontributors

%maybeusedtoendorseorpromoteproductsderivedfromthissoftware

%withoutspecificpriorwrittenpermission.

%

%THISSOFTWAREISPROVIDEDBYWILLIAMMARSHRICEUNIVERSITY,HOUSTON,TEXAS,

%ANDCONTRIBUTORSASISANDANYEXPRESSORIMPLIEDWARRANTIES,INCLUDING,

%BUTNOTLIMITEDTO,THEIMPLIEDWARRANTIESOFMERCHANTABILITYANDFITNESS

%FORAPARTICULARPURPOSEAREDISCLAIMED.INNOEVENTSHALLRICEUNIVERSITY

%ORCONTRIBUTORSBELIABLEFORANYDIRECT,INDIRECT,INCIDENTAL,SPECIAL,

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%PROCUREMENTOFSUBSTITUTEGOODSORSERVICES;LOSSOFUSE,DATA,ORPROFITS;

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%

%Forinformationoncommerciallicenses,contactRiceUniversity'sOfficeof

%TechnologyTransferattechtran@or(713)348-6173

if(nargin<2),

TYPE='min';

end;

if(rem(N,2)~=0),

error('NoDaubechiesfilterexistsforODDlength');

end;

K=N/2;

a=1;

p=1;

q=1;

h_0=[11];

forj=1:K-1,

a=-a*0.25*(j+K-1)/j;

h_0=[0h_0]+[h_00];

p=[0-p]+[p0];

p=[0-p]+[p0];

q=[0q0]+a*p;

end;

q=sort(roots(q));

qt=q(1:K-1);

ifTYPE=='mid',

ifrem(K,2)==1,

qt=q([1:4:N-22:4:N-2]);

else

qt=q([14:4:K-15:4:K-1N-3:-4:KN-4:-4:K]);

end;

end;

h_0=conv(h_0,real(poly(qt)));

h_0=sqrt(2)*h_0/sum(h_0); %Normalize