title: openpose compilation tells undefined reference to cv::VideoCapture::VideoCapture(cv::String const&)
body: <p>I have comipled caffe with GPU disabled,then</p>
  
  <pre><code>cp caffe/build/Makefile openpose/Makefile.conf
  </code></pre>
  
  <p>run</p>
  
  <pre><code> make all -j 6
  </code></pre>
  
  <p>got these errors:</p>
  
  <pre><code>-- Generating done
  -- Build files have been written to: /path/to/caffe/build
  CXX/LD -o ._release/examples/tutorial_thread/1_openpose_read_and_display.bin
  ._release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::VideoCapture(cv::String const&amp;)'
  ._release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::set(int, double)'
  ._release/lib/libopenpose.so: undefined reference to `op::renderPartAffinityFieldGpu(float*, op::PoseModel, cv::Size_&lt;int&gt; const&amp;, float const*, cv::Size_&lt;int&gt; const&amp;, float, int, float)'
  ._release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::release()'
  ._release/lib/libopenpose.so: undefined reference to `op::renderBodyPartsGpu(float*, op::PoseModel, cv::Size_&lt;int&gt; const&amp;, float const*, cv::Size_&lt;int&gt; const&amp;, float, float)'
  ._release/lib/libopenpose.so: undefined reference to `cv::VideoCapture::operator&gt;&gt;(cv::Mat&amp;)'
  </code></pre>
  
  <p>can't find opencv,and I compiled latest opencv 3.2-dev from source,all opencv programs(both c++ and python) worked,so why cann't openpose find opencv?</p>