///
another examples..
simple trackbar ex) in image
http://study.marearts.com/2016/07/opencv-30-trackbar-usage-simple-example.html
simple trackbar ex) in video
http://study.marearts.com/2016/07/opencv-30-trackbar-simple-example-in.html
string CstringToString(CString str) { CT2CA pszConvertedAnsiString(str); std::string s(pszConvertedAnsiString); return s; }..