adj_slowslantstackmeqn.m

beamlet变化的工具箱

function X = Adj_SlowSlantStackMeqN(S)
% Adj_SlowSlantStackMeqN: Adjoint Slant Stack Radon by Direct Algorithm
%  Usage:
%     X = Adj_SlowSlantStackMeqN(S)
%  Inputs:
%    S      n*2n matrix (t,theta)
%  Outputs:
%    X      n*n matrix (x,y)
%  Description:
%    Sums array along lines.
%  See Also:
%	 SlowSlantStack, FastSlantStack, Adj_FastSlantStack, Inv_FastSlantStack
%
	m = size(S,1);
	n = m;
%
	X = zeros(n,n);
	Y = zeros(m,n);
%
%	Mostly Horizontal
%
	for k= -(n/2-1) : (n/2),
		johan = S(:,n/2+1-k);
		s = 2*k/n;
		for i=1:n,
			cshift = Shift1dSignal(johan,-(i-(n/2+1))*s);
			Y(:,i) = Y(:,i) + cshift;
		end
	end
%
	X = X + Y;
%
	Y = zeros(m,n);
%
%	Mostly Vertical
%
	for k= (-n/2) : (n/2-1),
		johan = S(m:-1:1,3*n/2+k+1);
		s = 2*k/n;
		for i=1:n,
			cshift = Shift1dSignal(johan,-(i-(n/2+1))*s+1);
			Y(:,i) = Y(:,i) + cshift;
		end
	end
%
	X = X +  Y.';
%
%	Copyright (c) 2001 David L. Donoho
%
%
% Part of BeamLab Version:1.1
% Built:Thursday,14-Feb-2002 00:00:00
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail [e-mail]
%
%
% Part of BeamLab Version:200
% Built:Friday,23-Aug-2002 00:00:00
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail [e-mail]
%
%
% Part of BeamLab Version:200
% Built:Saturday,14-Sep-2002 00:00:00
% This is Copyrighted Material
% For Copying permissions see COPYING.m
% Comments? e-mail [e-mail]
%