&#160;</div><div class="line"><a name="l00066"></a><span class="lineno">   66</span>&#160;<span class="comment">// returns the first 3 elements of a 4-d vector</span></div><div class="line"><a name="l00067"></a><span class="lineno">   67</span>&#160;<span class="keyword">static</span> <span class="keyword">inline</span> cv::Vec3f head3(<span class="keyword">const</span> cv::Vec4f&amp; v) {</div><div class="line"><a name="l00068"></a><span class="lineno">   68</span>&#160;  <span class="keywordflow">return</