先抛出一个疑问，知道的希望留言解答下
（创建Application->Qt Console Application，代码与下面2、3一样，运行有时会显示图片，但大多数不显示，为什么？）
1、打开qt->创建工程->Non-Qi Project->Plain C++ Applicaton->完成
2、在.pro文件中加入如下
INCLUDEPATH += /usr/local/include/opencv/
/usr/local/include/opencv2/
/usr/local/include
LIBS += -lopencv_core\
-lopencv_imgproc\
-lopencv_highgui\
-lopencv_ml\
-lopencv_video\
-lopencv_features2d\
-lopencv_calib3d\
-lopencv_objdetect\
-lopencv_contrib\
-lopencv_legacy\
-lopencv_flann
3、.cpp中代码如下
#include<opencv2/opencv.hpp>
using namespace cv;
int main()
{
Mat I=imread("/home/jv/桌面/lena.png"); //桌面上放lena.png图片
namedWindow("1");
imshow("1",I);
waitKey(0);
return 0;
}