title: OpenCV opencv2/core/core.hpp: No such file or directory
body: <p>I'm creating a small project to test the opencv (2.4) on Android Studio 1.4 but when I try execute the app I have one problem with the NDK compiler. I think that the cpp files can't find the path to opencv but I dont know why.</p>
  
  <p>Any ideia how to fix this problem??</p>
  
  <p>Error:</p>
  
  <p><code>/home/User/AndroidStudioProjects/OpenCV/app/src/main/jni/native_processing.h
    Error:(10, 33) opencv2/core/core.hpp: No such file or directory</code></p>
  
  <p>JNI:</p>
  
  <p>OpenCV/app/src/main/jni/native_processing.cpp</p>
  
  <p>OpenCV/app/src/main/jni/native_processing.h</p>
  
  <pre><code>#ifndef OPENCV_SAMPLE_NATIVE_PROCESSING_H
  #define OPENCV_SAMPLE_NATIVE_PROCESSING_H
  
  #include &lt;jni.h&gt;
  
  #include &lt;opencv2/core/core.hpp&gt;
  #include &lt;opencv2/imgproc/imgproc.hpp&gt;
  #include &lt;opencv2/features2d/features2d.hpp&gt;
  #include &lt;vector&gt;
  
  extern "C" {
  JNIEXPORT void JNICALL      Java_com_projeto_opencv_MainActivity_FindFeatures(JNIEnv *, jobject,
                                                                                   jlong addrGray,
                                                                                   jlong addrRgba);
   }
   #endif
  </code></pre>
  
  <p>Android.mk</p>
  
  <pre><code>LOCAL_PATH := $(call my-dir)
  
  include $(CLEAR_VARS)
  OPENCV_CAMERA_MODULES:=on
  OPENCV_INSTALL_MODULES:=on
  OPENCV_LIB_TYPE:=STATIC
  
  
  PENCV_CAMERA_MODULES:=on
  OPENCV_INSTALL_MODULES:=on
  OPENCV_LIB_TYPE:=SHARED
  include /home/User/AndroidStudioProjects/OpenCV/OpenCV-android-sdk2/sdk/native/jni/OpenCV.mk
  
  LOCAL_C_INCLUDE :=/home/User/Download/OpenCV-android-sdk2/sdk/native/jni/include
  LOCAL_SRC_FILES := native_processing.cpp
  LOCAL_LDLIBS +=  -llog -ldl
  LOCAL_MODULE:= native_test
  
  
  include $(BUILD_SHARED_LIBRARY)
  </code></pre>
  
  <p>&nbsp;</p>
  
  <pre><code>Error: Warning:Native C/C++ source code is found, but it seems that
  NDK option is not configured.  Note that if you have an Android.mk, it is
  not used for compilation.  The recommended workaround is to remove the
  default jni source code directory by adding:
  
   android {
      sourceSets {
          main {
              jni.srcDirs = []
          }
      }
  }    
  
  to build.gradle, manually compile the code with ndk-build, and then
  place the resulting shared object in src/main/jniLibs.
  /home/User/AndroidStudioProjects/OpenCV/app/src/main/jni/native_processing.cpp
  Information:(1) (Unknown) In file included
  /home/User/AndroidStudioProjects/OpenCV/app/src/main/jni/native_processing.h
  Error:(10, 33) opencv2/core/core.hpp: No such file or directory
  compilation terminated.
  make: ***
   [/home/User/AndroidStudioProjects/OpenCV/app/build/intermediates/ndk/debug/obj/local/arm64-v8a/objs/app//home/geison/AndroidStudioProjects/OpenCV/app/src/main/jni/native_processing.o] Error 1
  :app:compileDebugNdk FAILED
  Error:Execution failed for task ':app:compileDebugNdk'.
  com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process 'command '/home/User/Android/Sdk/ndk-bundle/ndk-build'' finished with non-zero exit value 2
  </code></pre>