function collect_chars( fname )
% COLLECT_CHARS Collect training examples for OCR.
%
% Synopsis:
% collect_chars( fname )
%
% Description:
% It calls function that allows a user to draw examples
% of characters. The drawn characters are saved to the
% file fname whenever the middle mouse button is pressed.
%
% Input:
% fname [string] The filename to which the characters are saved.
%
% Example:
% Proceed as follows:
% 1) run function
% collect_chars('my_examples_1');
% 2) draw examples of numeral '1' (fill up the whole form);
% left button -> draw, middle button -> save it to file,
% right -> erase.
% 3) repeate the points 1) and 2) for numerals from 2 to 9, 0
% (use label 10 for numeral 0, i.e., collect_chars('my_examples_10'))
%
% (c) Statistical Pattern Recognition Toolbox, (C) 1999-2003,
% Written by Vojtech Franc and Vaclav Hlavac,
% <a href="http://www.cvut.cz">Czech Technical University Prague</a>,
% <a href="http://www.feld.cvut.cz">Faculty of Electrical engineering</a>,
% <a href="http://cmp.felk.cvut.cz">Center for Machine Perception</a>
% Modifications:
% 9-sep-03, VF
global FileName;
FileName = fname;
mpaper( {'fun','save_chars','width',16,'height',16});