makeaibdryfilter.sci

小波分解源代码

function EdgeFilt = MakeAIBdryFilter(D)
// MakeAIBdryFilter -- Edge filters for Average-Interpolating Wavelets
//  Usage
//    EdgeFilt = MakeAIBdryFilter(D)
//  Inputs
//    D         Degree of polynomial for average-interpolation.
//              Must be an even integer.
//  Outputs
//    EdgeFilt  Edge Filter suitable for use by
//              AIRefine, FWT_AI, IWT_AI, AIRefine2d, etc.
//  Description
//    Calculates average-interpolating filters of various orders
//    which may be used with FWT_AI and related tools.
//
//  See Also
//    AIRefine, FWT_AI, AIRefine2d
//
//  Copyright Aldo I Maalouf

if rem(D,2) | D < 2,
   EdgeFilt = [];
else

	// step 1. Moment matrix Mmat
	Mmat = zeros(D+1,D+1);
	for kp1 = 1:(D+1),
	   for lp1 = 1:(D+1),
			Mmat(lp1,kp1) = (lp1^kp1 - (lp1-1)^kp1)/kp1;
	   end
	end
	Minv = inv(Mmat);

	// step 2. Imputation matrx Jmat
	Jmat = zeros(D,D+1);
	for kpp1 = 1:(D+1),
	  for kp1 = 1:(D),
			Jmat(kp1,kpp1) = 2 * ((kp1/2)^kpp1 - (kp1/2 - .5)^kpp1)/(kpp1);
	  end
	end

	// step 3. Compose for prediction matrix:
	Pmat = Jmat * Minv ;
	EdgeFilt = Pmat;
end
endfunction