getUMatIndex     1254 modules/core/src/convert.cpp static void getUMatIndex(const std::vector<UMat> & um, int cn, int & idx, int & cnidx)
getUMatIndex     2075 modules/imgproc/src/histogram.cpp static void getUMatIndex(const std::vector<UMat> & um, int cn, int & idx, int & cnidx)