cvWaitKey

Waits for a pressed key

int cvWaitKey( int delay=0 );

delay

Delay in milliseconds.

Return

Maybe ASCII code

The function cvWaitKey waits for key event infinitely (delay<=0) or for "delay" milliseconds. Returns the code of the pressed key or -1 if no key were pressed until the specified timeout has elapsed.
Note: This function is the only method in HighGUI to fetch and handle events so it needs to be called periodically for normal event processing, unless HighGUI is used within some environment that takes care of event processing.