Fehler: CV ist kein Namespace-Namen mit dem Namespace CV.

#include <opencv/cv.h>


NOTE: you may forgotten to include above header, thats why you got below error.
prashad@ubuntu:~/test$ g++ create_ipl_image.cpp   `pkg-config opencv cvblob --cflags --libs` 
create_ipl_image.cpp:4:17: error: ‘cv’ is not a namespace-name
 using namespace cv;
Fragile Fish