配置QT Mingw & opencv

可以直接从这里下载别人构建好的

https://github.com/huihut/OpenCV-MinGW-Build

--------------------------------------------------------------------------

1、下载并安装QT5.12或更高版本，勾选MingW x64

2、把qt bin目录加入PATH：

C:QtQt5.12.15.12.1mingw73_64in

C:QtQt5.12.1Toolsmingw730_64in

3、下载opencv4.0或更高版本，解压为 D:softwareopencvsources

4、下载CMake3.14或更高版本，安装时选择把bin目录加入PATH

5、安装python2.7.16，安装时选择把bin目录加入PATH

6、安装JDK1.8

7、启动CMake，输入源代码和构建目录：

源代码目录：D:softwareopencvsources

构建目录：D:softwareopencvuild

点击左下角的Configuration按钮，选择构建模式为MingGW makefiles，选择 Native Compiler，选择C和C++编辑器的位置：

C:QtQt5.12.1Toolsmingw730_64ingcc.exe

C:QtQt5.12.1Toolsmingw730_64ing++.exe

然后等待配置。

8、配置完成后，勾选WITH_OPENGL和WITH_QT两项，选择CMAKE_BUILD_TYPE为Release，再次configure。

9、正式开始构建

cd D:softwareopencvuild

mingw32-make -j 8

mingw32-make install

-------------------------------------------------------------------------------------------------

新建一个QT项目，修改.pro文件，加入：

INCLUDEPATH += D:softwareOpenCV-MinGW-Build-OpenCV-4.0.1-x64include

LIBS += D:softwareOpenCV-MinGW-Build-OpenCV-4.0.1-x64x64mingwinlibopencv_core401.dll
LIBS += D:softwareOpenCV-MinGW-Build-OpenCV-4.0.1-x64x64mingwinlibopencv_highgui401.dll
LIBS += D:softwareOpenCV-MinGW-Build-OpenCV-4.0.1-x64x64mingwinlibopencv_imgproc401.dll
LIBS += D:softwareOpenCV-MinGW-Build-OpenCV-4.0.1-x64x64mingwinlibopencv_calib3d401.dll
LIBS += D:softwareOpenCV-MinGW-Build-OpenCV-4.0.1-x64x64mingwinlibopencv_imgcodecs401.dll
LIBS += D:softwareOpenCV-MinGW-Build-OpenCV-4.0.1-x64x64mingwinlibopencv_videoio401.dll

修改main.cpp，如下：

#include "widget.h"
#include <QApplication>

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>

using namespace cv;
using namespace std;

int main(int argc, char *argv[])
{
    Mat image = imread("C:\Users\Administrator\Desktop\1.bmp", 0);
    namedWindow("image");
    imshow("image", image);

    Mat contours;
    Canny(image,    //灰度图
        contours,   //输出轮廓
        125,    //低阈值
        350);   //高阈值

    //因为正常情况下轮廓是用非零像素表示 我们反转黑白值
    Mat contoursInv;    //反转后的图像
    threshold(contours,
        contoursInv,
        128,    //低于该值的像素
        255,    //将变成255
        THRESH_BINARY_INV);
    namedWindow("contoursInv");
    imshow("contoursInv", contoursInv);

    waitKey(0);
    return 0;
}