function outpoints = icbm_fsl2tal(inpoints)
%
% This function converts coordinates from MNI space (normalized 
% using the FSL software package) to Talairach space using the 
% icbm2tal transform developed and validated by Jack Lancaster 
% at the Research Imaging Center in San Antonio, Texas.
%
% http://www3.interscience.wiley.com/cgi-bin/abstract/114104479/ABSTRACT
% 
% FORMAT outpoints = icbm_fsl2tal(inpoints)
% Where inpoints is N by 3 or 3 by N matrix of coordinates
% (N being the number of points)
%
% ric.uthscsa.edu 3/14/07

dimdim = find(size(inpoints) == 3);
if isempty(dimdim)
  error('input must be a N by 3 or 3 by N matrix')
end
if dimdim == 2
  inpoints = inpoints';
end

% Transformation matrices, different for each software package
icbm_fsl = [0.9464 0.0034 -0.0026 -1.0680
		   -0.0083 0.9479 -0.0580 -1.0239
            0.0053 0.0617  0.9010  3.1883
            0.0000 0.0000  0.0000  1.0000];

% apply the transformation matrix
inpoints = [inpoints; ones(1, size(inpoints, 2))];
inpoints = icbm_fsl * inpoints;

% format the outpoints, transpose if necessary
outpoints = inpoints(1:3, :);
if dimdim == 2
  outpoints = outpoints';
end