function chars = getCharSizes(axis)
% Copyright 2010, Joseph O. Deasy, on behalf of the CERR development team.
% 
% This file is part of The Computational Environment for Radiotherapy Research (CERR).
% 
% CERR development has been led by:  Aditya Apte, Divya Khullar, James Alaly, and Joseph O. Deasy.
% 
% CERR has been financially supported by the US National Institutes of Health under multiple grants.
% 
% CERR is distributed under the terms of the Lesser GNU Public License. 
% 
%     This version of CERR 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.
% 
% CERR 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 CERR.  If not, see <http://www.gnu.org/licenses/>.


axes(axis);
oldUnits = get(axis, 'units');
set(axis, 'units', 'pixels');
h = text(1, 1, 1, '||', 'margin', .01, 'interpreter', 'none', 'units', 'pixels');
extent = get(h, 'extent');
delete(h);
baseline = extent(3);

for i=0:255
    h = text(1, 1, 1, ['|' char(i) '|'], 'margin', .01, 'interpreter', 'none', 'units', 'pixels');
    extent = get(h, 'extent');
    output(i+1) = extent(3) - baseline;
    delete(h);
end
chars = output;
set(axis, 'units', oldUnits);