title: opencv_contrib compilation error: class has no member
body: <p>I have to implement the SURF algorithm for image stitching. I was having trouble with the libraries, as listed <a href="https://stackoverflow.com/questions/33560251/opencv-3-0-0-ubuntu-14-04-nonfree-nonfree-hpp-build-error">here</a></p>
  
  <p>After trying the solutions I could find, I removed the opencv and started to build from scratch. I tried to include the 'opencv_contrib' library during installation, but it didn't work.</p>
  
  <p>So I installed opencv, and then tried to integrate the package as told int he <a href="https://github.com/Itseez/opencv_contrib" rel="nofollow">github repository</a> of the package. During the<br>
      make -j2 
  line, I keep getting the following error.</p>
  
  <pre><code>[ 77%] Building CXX object modules/ximgproc/CMakeFiles/opencv_ximgproc.dir/src/sparse_match_interpolators.cpp.o
  In file included from /home/akshat/OpenCV/opencv-3.0.0/modules/core/include/opencv2/core.hpp:54:0,
                   from /home/akshat/OpenCV/opencv-3.0.0/build/modules/ximgproc/precomp.hpp:40:
  /home/akshat/opencv_contrib/modules/ximgproc/src/sparse_match_interpolators.cpp: In member function ‘virtual void cv::ximgproc::EdgeAwareInterpolatorImpl::interpolate(cv::InputArray, cv::InputArray, cv::InputArray, cv::InputArray, cv::OutputArray)’:
  /home/akshat/opencv_contrib/modules/ximgproc/src/sparse_match_interpolators.cpp:171:52: error: ‘const class cv::_InputArray’ has no member named ‘isVector’
       CV_Assert( !from_points.empty() &amp;&amp; from_points.isVector() &amp;&amp;
                                                      ^
  /home/akshat/OpenCV/opencv-3.0.0/modules/core/include/opencv2/core/base.hpp:389:33: note: in definition of macro ‘CV_Assert’
   #define CV_Assert( expr ) if(!!(expr)) ; else cv::error( cv::Error::StsAssert, #expr, CV_Func, __FILE__, __LINE__ )
                                   ^
  /home/akshat/opencv_contrib/modules/ximgproc/src/sparse_match_interpolators.cpp:172:52: error: ‘const class cv::_InputArray’ has no member named ‘isVector’
                  !to_points  .empty() &amp;&amp; to_points  .isVector() &amp;&amp;
                                                      ^
  /home/akshat/OpenCV/opencv-3.0.0/modules/core/include/opencv2/core/base.hpp:389:33: note: in definition of macro ‘CV_Assert’
   #define CV_Assert( expr ) if(!!(expr)) ; else cv::error( cv::Error::StsAssert, #expr, CV_Func, __FILE__, __LINE__ )
                                   ^
  make[2]: *** [modules/ximgproc/CMakeFiles/opencv_ximgproc.dir/src/sparse_match_interpolators.cpp.o] Error 1
  make[1]: *** [modules/ximgproc/CMakeFiles/opencv_ximgproc.dir/all] Error 2
  make: *** [all] Error 2
  </code></pre>
  
  <p>Thanks in advance </p>