StsNullPtr        187 modules/highgui/src/window_QT.cpp         CV_Error(Error::StsNullPtr, "NULL guiReceiver (please create a window)");
StsNullPtr        848 modules/highgui/src/window_carbon.cpp         CV_Error(Error::StsNullPtr, "NULL window");
StsNullPtr        747 modules/highgui/src/window_gtk.cpp         CV_Error(Error::StsNullPtr, "NULL window");
StsNullPtr        504 modules/highgui/src/window_w32.cpp         CV_Error(Error::StsNullPtr, "NULL window");