What is the purpose of _c.h files?

edit

usually they contain the old c-api functionality.

you should never need to include them directly

to access the c-api, you'd go like:

#include <opencv/highgui.h>

for the c++ (2.x) api:

#include <opencv2/highgui/highgui.hpp>

don't resolve to hacking, you won't get far that way.

there must be something wrong in your vcproj file, or the install.

there's 2 ways to get the headers right:

• easy(using the prebuilt stuff:

  point your "Additional Include Dirs" at opencv/build/include

  (it should just work , if that folder contains all the nessecary headers).

  note that if you build your own libs, cmake might install the headers in a "build/install/include" folder, check with cmake-gui, where things go!

• hard(but safe):

  point your "Additional Include Dirs" at opencv/include, additionally for each module, add it's module path, like opencv/modules/highgui/include opencv/modules/core/include ,...

  more work, but this way, you don't depend on install things. (that's what cmake does, when you ask it to generate your own project depending on opencv)