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

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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:\Qt\Qt5.12.1\5.12.1\mingw73_64\bin

C:\Qt\Qt5.12.1\Tools\mingw730_64\bin

3、下载opencv4.0或更高版本，解压为 D:\software\opencv\sources

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:\software\opencv\sources

构建目录：D:\software\opencv\build

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:\Qt\Qt5.12.1\Tools\mingw730_64\bin\gcc.exe

C:\Qt\Qt5.12.1\Tools\mingw730_64\bin\g++.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:\software\opencv\build

mingw32-make -j 8

mingw32-make install

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新建一个QT项目，修改.pro文件，加入：

INCLUDEPATH += D:\software\OpenCV-MinGW-Build-OpenCV-4.0.1-x64\include

LIBS += D:\software\OpenCV-MinGW-Build-OpenCV-4.0.1-x64\x64\mingw\bin\libopencv_core401.dll
LIBS += D:\software\OpenCV-MinGW-Build-OpenCV-4.0.1-x64\x64\mingw\bin\libopencv_highgui401.dll
LIBS += D:\software\OpenCV-MinGW-Build-OpenCV-4.0.1-x64\x64\mingw\bin\libopencv_imgproc401.dll
LIBS += D:\software\OpenCV-MinGW-Build-OpenCV-4.0.1-x64\x64\mingw\bin\libopencv_calib3d401.dll
LIBS += D:\software\OpenCV-MinGW-Build-OpenCV-4.0.1-x64\x64\mingw\bin\libopencv_imgcodecs401.dll
LIBS += D:\software\OpenCV-MinGW-Build-OpenCV-4.0.1-x64\x64\mingw\bin\libopencv_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", );
    namedWindow("image");
    imshow("image", image);

    Mat contours;
    Canny(image,    //灰度图
        contours,   //输出轮廓
        ,    //低阈值
        );   //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,
        ,    //低于该值的像素
        ,    //将变成255
        THRESH_BINARY_INV);
    namedWindow("contoursInv");
    imshow("contoursInv", contoursInv);

    waitKey();
    return ;
}