12             img = -img+flipper;
0113         <span class="keyword">elseif</span> (strcmp(opt1,<span class="string">'pos'</span>) == 1)
0114             img = img;
0115         <span class="keyword">end</span>
0116          
0117         <span class="comment">% Calculate square of difference image (to reduce noise) and track</span>
0118         temp = (img-background).^2;
0119               
0120         [x_raw y_raw bodyline sqr]=<a href="FindFly.html" class="code" title="function [x, y, bodyline, sqr] =