makeaisegfilter.m

老外写的小波变换的工具箱

function SegFilt = MakeAISegFilter(D,eta0)
% MakeAISegFilter -- Extract coefficients for segmented B/W Transform
%  Usage
%    SegFilt = MakeAISegFilter(D,eta0)
%

	if rem(D,2) | D < 2,
	   EdgeFilt = [];
	else
	% step 0. Get the rounded representation
	if eta0 > .5 ,  
	   flip =1; 
	   eta0 = 1-eta0; 
	else 
	   flip = 0; 
	end;
	% step 1. Moment matrix Mmat
	Mmat = zeros(2*D+2,2*D+2);
	for kp1 = 1:(D+1),
	   for lp1 = (-D):0,
	        Mmat(D+1+lp1,kp1) = (lp1^kp1 - (lp1-1)^kp1)/kp1;
	   end
	end
	for kp1 = 1:(D+1),
	   for lp1 = 2:(D+1),
	        Mmat(D+1+lp1,D+1+kp1) = (lp1^kp1 - (lp1-1)^kp1)/kp1;
	   end
	end
	for kp1 = 1:(D+1),
	   Mmat(D+2,kp1)     = (eta0^kp1)/kp1;
	   Mmat(D+2,D+1+kp1) = (1 - eta0^kp1)/kp1;
	end
	Minv = inv(Mmat);
	% step 2. Imputation matrx Jmat
	Jmat = zeros(2,2*D+2);
	for kpp2 = 1:(D+1),
	       Jmat(2,D+1+kpp2) = 2 * ((1)^kpp2 -  (.5)^kpp2)/(kpp2);
	end
	for kpp1 = 1:(D+1),
	   Jmat(1,kpp1)     =  2 * (eta0^kpp1)/kpp1;
	   Jmat(1,D+1+kpp1) =  2 * (.5^kpp1 - eta0^kpp1)/kpp1 ;
	end
	% step 3. Compose for prediction matrix:
	Pmat = Jmat * Minv ;
	Pmat = [Pmat zeros(2,1)];
	if flip==0,
	   SegFilt = Pmat;
	else
	   SegFilt = Pmat(2:-1:1,(2*D+3):-1:1);
	end
	end
	
	
	
	
    
    
 
 
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