详情参考：https://blog.csdn.net/qq_25343557/article/details/78654011
添加一个计算程序运行时间的代码
double t = getTickCount();
/* ...
... */
double timeconsume = (getTickCount()-t)/getTickFrequency();
print("Time consume %.3f",timeconsume);if(!src.data) = if(src.empty())
参考：https://blog.csdn.net/flyyufenfei/article/details/79207842