ImageFileOutImpl

Resets framesWritten.

Invoked by Akka after processing of external events stopped because the operator is about to stop or fail. Calls stopped and then removes the node from the control.

Final so we don't accidentally place code here. In order to initialize state, use NodeHasInitImpl and implement init.

Called after a window has been fully read in.

Tries to prepare the parameters for the next window. If successful, returns true otherwise false. If successful, it must be possible to successively call readWinSize. Most likely, the implementation will allocate an internal window buffer here.