基于ubuntu+opencv+qt实现的简单人脸识别

做这个也是被课设所逼迫，弄了个看着还挺高大上的东西，我这个小白还是记录一下吧
其实前期主要是在安装和配置环境这哉了好几天了，后来在b站上看到一个视频顿时开窍了，视频里用的是opencv3.3+opencv-contrib3.3，但是我安装的时候发现还是有点问题，因为缺少的.i文件好像加不进去，所以我就换成了4.3.0的版本，就一点毛病都没有了，注意opencv和contrib的版本要一样。
还有就是不要在共享目录下面安装opencv，不然编译时会出问题。
附上视频链接：

https://www.bilibili.com/video/BV1MK411A7XT

缺少的文件和放的位置视频里都有讲，跟着视频走就完事，我这里就不再赘述了。
其实这里还有个地方就是可能在运行失败的时候会提示没有链接成功，在没用qt进行开发的时候，需在cmakeList.txt里面添加相应的库、库路径和头文件路径
如下（改成你自己相应的目录和库）：
set(OpenCV_INCLUDE_DIRS /home/china/opencv/opencv-4.3.0_install/include/opencv4/opencv2) set(OpenCV_LIB_DIR /home/china/opencv/opencv-4.3.0_install/lib) set(OpenCV_LIBS /home/china/opencv/opencv-4.3.0_install/lib/libopencv_face.so /home/china/opencv/opencv-4.3.0_install/lib/libopencv_freetype.so /usr/lib/x86_64-linux-gnu/libsqlite3.so.0 )
还有最下面需要改成：

# Link your application with OpenCV libraries
target_link_libraries(opencv_t PRIVATE ${OpenCV_LIBS} )

这样就不会报链接错误了
其实大部分错误都是库没找到或者相应头文件没找到，只要动动手指改一改就可以了。
如果这个不够详细的话可以看看这位的博客：

https://blog.csdn.net/shanyicheng1111/article/details/77485926

代码在ubuntu上能编译运行后，就想着放到qt上去了，其实这个时候也就和前面大同小异了，各种库各种头文件，我后面还把数据库给加进去了，显得可能比较乱。
附上部分代码：
pro文件

#-------------------------------------------------
#
# Project created by QtCreator 2020-11-21T11:34:13
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = opencv_qt
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which as been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0


SOURCES += \
        main.cpp \
        mainwindow.cpp \
    form.cpp

HEADERS += \
        mainwindow.h \
    form.h

INCLUDEPATH += /mnt/hgfs/share/opencv \
                /usr/local/include\
                /home/china/opencv/opencv-4.3.0_install/include/opencv4/opencv2 \
            /home/china/opencv/opencv-4.3.0_install/include/opencv4 \
               /usr/local/include/opencv \
               /usr/local/include/opencv2


LIBS += /home/china/opencv/opencv-4.3.0_install/lib/libopencv_highgui.so     \
        /home/china/opencv/opencv-4.3.0_install/lib/libopencv_face.so  \
         /home/china/opencv/opencv-4.3.0_install/lib/libopencv_freetype.so    \
         /home/china/opencv/opencv-4.3.0_install/lib/libopencv_core.so      \
         /home/china/opencv/opencv-4.3.0_install/lib/libopencv_imgproc.so   \
          /home/china/opencv/opencv-4.3.0_install/lib/libopencv_imgcodecs.so     \
        /home/china/opencv/opencv-4.3.0_install/lib/libopencv_objdetect.so  \
/home/china/opencv/opencv-4.3.0_install/lib/libopencv_calib3d.so  \
/home/china/opencv/opencv-4.3.0_install/lib/libopencv_dnn.so  \
/home/china/opencv/opencv-4.3.0_install/lib/libopencv_features2d.so  \
/home/china/opencv/opencv-4.3.0_install/lib/libopencv_flann.so  \
/home/china/opencv/opencv-4.3.0_install/lib/libopencv_video.so \
/home/china/opencv/opencv-4.3.0_install/lib/libopencv_videoio.so \
/home/china/opencv/opencv-4.3.0_install/lib/libopencv_photo.so \
/home/china/opencv/opencv-4.3.0_install/lib/libopencv_stitching.so \
/home/china/opencv/opencv-4.3.0_install/lib/libopencv_gapi.so \
/home/china/opencv/opencv-4.3.0_install/lib/libopencv_ml.so \
/usr/lib/x86_64-linux-gnu/libsqlite3.so.0\




FORMS += \
        mainwindow.ui \
    form.ui

RESOURCES += \
    ziti.qrc \
    1.qrc

//mainwindow.cpp用于实现人脸识别和录入的主要功能
/*
 * 人名和标签主要使用sqlite3数据库存储，图片库的的图片名和标签用name.txt文件存贮，
  图片和人名的联系主要通过标签索引
*/
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include
#include"face.hpp"
#include
#include 
#include 
#include 
#include "face/facerec.hpp"
#include 
#include
#include
//#include
#include
#include
#include
#include

using namespace cv;
using namespace cv::face;
using namespace std;
//人脸识别库
string haar_face_datapath="haarcascade_frontalface_alt_tree.xml";
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    form = new Form;
    connect(form,SIGNAL(sig_in(QString)),this,SLOT(name_in(QString)));
}

MainWindow::~MainWindow()
{
    delete ui;
}


//初始化数据库
int init_db(sqlite3* db)
{

    int flag;
    char *errmsg;
    //创建表
    const char *sql="create table opencv_t(num int primary key,name text(255) not null);";
    //计算数据库的总行数，以便之后的索引
    const char *sql1="select count(*) from opencv_t; ";
     sqlite3_stmt *stmt = NULL; 	   //stmt语句句柄
    int result = sqlite3_prepare_v2(db, sql, -1, &stmt, NULL);
    sqlite3_step(stmt);

    sqlite3_prepare_v2(db, sql1, -1, &stmt, NULL);
    sqlite3_step(stmt);
    int result1 = sqlite3_column_int(stmt,0);
    cout< images;
        vector labels;
        //用分号把姓名和标签分开
        char separator = ';';
        while(getline(file,line))
        {
            stringstream liness(line);
            getline(liness,path,separator);     //获取人脸图片库路径
            getline(liness,classlabel);            //获取人脸标签
            if(!path.empty() && !classlabel.empty())
            {
                images.push_back(imread(path,0));
                labels.push_back(atoi(classlabel.c_str()));

            }
        }

        if(images.size()<1 || labels.size()<1)
        {
            printf("invaild image path\n");
            return ;
        }
        int height=images[0].rows;
        int width= images[0].cols;
        printf("heiget: %d ,width: %d \n",height,width);
        Mat testSample =images[images.size()-1];
        int testLabel=labels[labels.size()-1];
        images.pop_back();
        labels.pop_back();
        //三种人脸识别算法
    //	Ptrmodel =FisherFaceRecognizer::create();
        Ptrmodel =LBPHFaceRecognizer::create();
    //	Ptrmodel =EigenFaceRecognizer :: create();
        //进行模型训练
        model->train(images,labels);
        int predictedLabel=model->predict(testSample);
        printf("actual label: %d,predict label: %d\n",testLabel,predictedLabel);

        CascadeClassifier faceDetector;
        faceDetector.load(haar_face_datapath);      //加载人脸数据
        //打开摄像头
        VideoCapture capture(0);
        if(!capture.isOpened())
        {
            cout<<"打开失败！！"< ft2;
        ft2=freetype::createFreeType2();
        ft2->loadFontData("./simhei.ttf",0);

        Mat frame;
        //namedWindow("人脸识别",CV_WINDOW_AUTOSIZE);
        vector faces;
        Mat dst;
        //读取面部
        while(capture.read(frame))
        {
            flip(frame,frame,1);

            faceDetector.detectMultiScale(frame,faces,1.1,1,0,Size(80,100),Size(380,400));
            for(int i=0;ipredict(testSample);
                //用矩形框出来
                rectangle(frame,faces[i],Scalar(255,0,0),2,8,0);

                string text;

                 //在数据库中查找人脸标签，如果找到就输出人名
                char sql[128] = {0};
                sprintf(sql,"select * from opencv_t where num=%d;",label);
               // cout<putText(frame,(char *)names,cvPoint(faces[i].x,faces[i].y -10),40,Scalar(255,0,0),-1,8,true);
                    cout << names< faces;
    //faceCascade.detectMultiScale(imgGray, faces,1.2,5,0,Size(30,30));
    while(capture.read(frame))
    {
      flip(frame, frame ,1);
      faceDetector.detectMultiScale(frame, faces,1.1,1,0,Size(100,100));
      for(int i =0 ;ishow();
}


void MainWindow::name_in(QString na)
{
    qDebug()<<"------"<