## Copyright (C) 2015 Loriane Weber
## 
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or
## (at your option) any later version.
## 
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
## 
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## CTFPropagation 1D

## Author: Loriane Weber <lweber@gpid16a-1801>
## Created: 2015-11-20

function [ Id ] = CTFPropagation_1D (ph, B, D, lambda, oversamp, ftot)

[mp, np]=size(ph);

if(np!=1)
	disp('error')
	return
end

%% propagators in 1D (sin and cos)
ssq=2*ssquare1(lambda*D, ftot, 1)'; 
csq=2*csquare1(lambda*D, ftot, 1)'; 

tmp_B=zeros(2*mp, 1);
tmp_ph=zeros(2*mp, 1);
tmp_B(1:mp,1)=B;
tmp_ph(1:mp,1)=ph;
		
% fourier domain
tmp_B=fft(tmp_B);
tmp_ph=fft(tmp_ph);

tmp_Id=-csq.*tmp_B + ssq.*tmp_ph;
tmp_Id=1+real(ifft(tmp_Id));
	

Id=tmp_Id(1:mp, 1);
			
	if oversamp==2
		ipf = [0.5 1 0.5]; % modelise le binning du detecteur
		Idd = conv(Id,ipf,'same')./conv(ones(size(Id)),ipf,'same');
		Idd = Idd(oversamp:oversamp:end, :);
		Id=Idd; 
	elseif oversamp==4
		ipf = [0.5 1.0 1.0 1.0 0.5]; % modelise le binning du detecteur
		Idd = conv(Id,ipf,'same')./conv(ones(size(Id)),ipf,'same');
		Idd = Idd(oversamp:oversamp:end, :);

		
		Id=Idd; 
	end % oversamp


endfunction
