function img2svg(filename,folder)

% usage: 
% (1) Start Matlab and go to the folder that your original image is in.
% (2) Type img2svg(<filename>) and hit enter (replace <filename> : name of original image file)
% An SVG file with the same name is then created at the current folder.

if nargin < 2
    folder = '.';
end

% by Zhangzhang Si, May 6, 2009, zhangzhang.si@gmail.com

% This code simply create an .svg file, with a link pointing to 
%   <filepath>. The .svg file is in the same folder as the original image.

% extract the postfix
bvec = filename=='.';
ind = find(bvec);
ind = ind(end);
% postfix = filename(ind:end);
outfilepath = [folder '/' filename(1:ind-1) '.svg'];

im = imread([folder '/' filename]);
[sx sy c] = size(im);

fid = fopen(outfilepath,'w');

formatSVG = '<?xml version="1.0" standalone="no"?>';
fprintf(fid,formatSVG);
formatSVG = [ '\n<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">']; 
fprintf(fid,formatSVG);
formatSVG = [ '\n<svg preserveAspectRatio="xMinYMin meet" width="100%%" height="100%%" viewBox="0 0 %d %d"   version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">'];
fprintf(fid,formatSVG,sy,sx);

formatSVG = [ '\n<rect x="0" y="0" width="%d" height="%d" fill="#ffffff" stroke="none" />'];
fprintf(fid,formatSVG,sy,sx);
formatSVG = [ '\n<g> <clipPath id="ID000000">  <rect x="0" y="0" width="%d" height="%d"/> </clipPath> <g>'];
fprintf(fid,formatSVG,sy,sx);
formatSVG = [ '\n<g clip-path="url(#ID000000)">'];
fprintf(fid,formatSVG);
formatSVG = [ '\n<image x="0" y="0" width="%d" height="%d" image-rendering="optimizeSpeed" preserveAspectRatio="none" xlink:href="%s" />'];
fprintf(fid,formatSVG,sy,sx,filename);
formatSVG = [ '\n</g> </g> </g> </svg>'];
fprintf(fid,formatSVG);
fclose(fid);
disp(['transformed ' filename]);