function png2gif(png, gif)
% PNG2GIF   - Create a gif file from a png file
% 
% Use as: png2gif(png, gif)
% Inputs: png = Name of png image file to be converted
%         gif = Name of the gif file to write to.
% 
% PNG2GIF uses Matlab's java interface to call the static method
% 'convert' in the java class 'PngToGif'. It requires two freely
% available java packages and the class PngToGif to be on MATLAB's
% classpath:
% 
% The packages required are:
%   1. The java PNG library to decode PNG images. Distributed under the
%      GNU GPL. http://www.visualtek.com/PNG/index.html
%   2. ACME java library to encode the GIF images. Distributed free for 
%      any kind of use (Commercial, Educational, whatever).
%      http://www.acme.com/resources/classes/Acme.tar.Z
%   3. PngToGif.class
%
% The following is a quote from Matlab's solution seach:
%   For MATLAB to see your classes they must be in a directory on 
%   MATLAB's classpath (that's classpath, NOT MATLABPATH). MATLAB's 
%   classpath is kept in a file called classpath.txt in your 
%   toolbox/local directory (type which classpath.txt at the MATLAB 
%   prompt). Add the full path to the directory containing your .class 
%   files to this file. Classpath.txt is only read once when MATLAB 
%   starts, so changes to it or your .class files require you to restart
%   MATLAB before they will take effect.

if nargin < 2
   error('Usage: png2gif(PNGFileIn,GIFFileOut)');
end

java('on');
java_method('convert', 'PngToGif', png, gif);