OpenCV undefined references [duplicate]

Answer 1

You can also look at the output of pkg-config --static --libs opencv to arrange the libraries in the correct order.

Answer 2

You are missing opencv_highgui and probably opencv_features2d as well.

cv::rectangle is defined at opencv_core.

Make sure that your file is being linked with all these libraries.

Answer 3

The problem was in the libraries order. The correct order is:

LOCAL_STATIC_LIBRARIES :=  libopencv_calib3d opencv_features2d opencv_flann opencv_imgproc opencv_core

So the main principle is you have to declare libraries in reverse order of their dependency (e.g. *opencv_imgproc* depends on *opencv_core* and *opencv_features2d* depends on *opencv_imgproc* and so on).