I have some simple opencv files which I wanted to compile on 12.04. I have installed all the -dev packages They use: #include <cv.h> #include <highgui.h> at the top of the file. Using g++ `pkg-config --cflags --libs opencv` canny.cpp gives cv.h: No such file or directory pkg-config seems to list /usr/include/opencv but the directory created at install is /usr/include/opencv2 Is this a bug? Any advice?