cv::Mat img = cv::imread(\"../赤月/lena.jpg\");
if(img.empty()) std::cout<<\"empty image\"<
Or
QString const i
After Niko show me the link, I know how to solve the problem by Qt
QTextCodec *codec = QTextCodec::codecForName("UTF-8");
QTextCodec::setCodecForLocale(codec);
QTextCodec::setCodecForCStrings(codec);
QTextCodec::setCodecForTr(codec);
QString const image_name = "../赤月/lena.jpg";
cv::Mat img = cv::imread(image_name_.toAscii().constData());
Now the codes work perfectly, thanks to all of you.