[ros-users] A question about OpenCV

I use the package opencv2, and included "opencv/cv.h". It reports a

warning:
     #warning "This is a deprecated opencv header provided for 
compatibility. Please include a header from a corresponding opencv module"

I haven't been staying in this developing track. It seems that cv.h is
deprecated in Version 2 (or 2.1?).

What would be the right way then to include opencv headers? -- It
would be further appreciated if anyone can point me to the reason of
that being deprecated.

Thanks!

Hao