Hi all,<br><br>I was just looking at the iso-contouring code of Zach Pincus (<a href="http://mail.scipy.org/pipermail/scipy-user/2009-July/021719.html">http://mail.scipy.org/pipermail/scipy-user/2009-July/021719.html</a>), and saw it is implemented with the marching squares algorithm. On the task list that algorithm is listed as well, with a note to investigate patent issues. So I had a look at that.<br>
<br>The patent issue was earlier raised in this thread in 2004: <a href="http://osdir.com/ml/python.matplotlib.devel/2004-10/msg00066.html">http://osdir.com/ml/python.matplotlib.devel/2004-10/msg00066.html</a>. The open question was whether marching squares was covered under the patent for marching cubes or not. This is a 1985 patent and has expired in the meantime, as noted here: <a href="http://en.wikipedia.org/wiki/Marching_cubes">http://en.wikipedia.org/wiki/Marching_cubes</a>.<br>
<br>IANAL, but I think there are no patent issues anymore.<br><br><br>Separate question to Zach: the code you sent to the SciPy list in July was GPL licensed. You noted you were willing to send it again under a different license. Could you please send it to the list with a BSD/MIT/similar license?<br>
<br>Cheers,<br>Ralf<br><br>