【转】PCA算法学习_1(OpenCV中PCA实现人脸降维)

#ifndef PCAFACE_H
#define PCAFACE_H
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>

using namespace cv;

#include <QDialog>

namespace Ui {
class PCAFace;
}

class PCAFace : public QDialog
{
    Q_OBJECT
    
public:
    explicit PCAFace(QWidget *parent = 0);
    ~PCAFace();

    Mat normalize(const Mat& src);

    
protected:
    void changeEvent(QEvent *e);
    
private slots:
    void on_startButton_clicked();

    void on_closeButton_clicked();

private:
    Ui::PCAFace *ui;
    Mat src_face1, src_face2, src_face3;
    Mat project_face1, project_face2, project_face3;
    Mat dst;
    Mat pca_face1, pca_face2, pca_face3;
    vector<Mat> src;
    int total;
};

#endif // PCAFACE_H

#include "pcaface.h"
#include "ui_pcaface.h"
#include <QString>
#include <iostream>
#include <stdio.h>

using namespace std;

PCAFace::PCAFace(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::PCAFace)
{
    ui->setupUi(this);
    src_face1 = imread("./images/1.pgm", 0);
    //下面的代码为设置图片显示区域自适应图片的大小
    ui->face1Browser->setFixedHeight(src_face1.rows+1);
    ui->face1Browser->setFixedWidth(src_face1.cols+1);
    ui->face2Browser->setFixedHeight(src_face1.rows+1);
    ui->face2Browser->setFixedWidth(src_face1.cols+1);
    ui->face3Browser->setFixedHeight(src_face1.rows+1);
    ui->face3Browser->setFixedWidth(src_face1.cols+1);

    ui->face4Browser->setFixedHeight(src_face1.rows+1);
    ui->face4Browser->setFixedWidth(src_face1.cols+1);
    ui->face5Browser->setFixedHeight(src_face1.rows+1);
    ui->face5Browser->setFixedWidth(src_face1.cols+1);
    ui->face6Browser->setFixedHeight(src_face1.rows+1);
    ui->face6Browser->setFixedWidth(src_face1.cols+1);

    ui->face7Browser->setFixedHeight(src_face1.rows+1);
    ui->face7Browser->setFixedWidth(src_face1.cols+1);
    ui->face8Browser->setFixedHeight(src_face1.rows+1);
    ui->face8Browser->setFixedWidth(src_face1.cols+1);
    ui->face9Browser->setFixedHeight(src_face1.rows+1);
    ui->face9Browser->setFixedWidth(src_face1.cols+1);

    for(int i = 1; i <= 15; i++)
    {
        stringstream ss;
        string num;
        ss<<i;//将整数i读入字符串流
        ss>>num;//将字符串流中的数据传入num，这2句代码即把数字转换成字符
        string image_name = ("./images/" + num + ".pgm");//需要读取的图片全名
        src.push_back(imread(image_name, 0));
    }
    total= src[0].rows*src[0].cols;
}

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

void PCAFace::changeEvent(QEvent *e)
{
    QDialog::changeEvent(e);
    switch (e->type()) {
    case QEvent::LanguageChange:
        ui->retranslateUi(this);
        break;
    default:
        break;
    }
}

//将Mat内的内容归一化到0～255，归一化后的类型为但通道整型
Mat PCAFace::normalize(const Mat& src) {
    Mat srcnorm;
    cv::normalize(src, srcnorm, 0, 255, NORM_MINMAX, CV_8UC1);
    return srcnorm;
}


void PCAFace::on_startButton_clicked()
{
    //先显示3张原图
    ui->face1Browser->append("<img src=./images/1.pgm>");
    ui->face2Browser->append("<img src=./images/7.pgm>");
    ui->face3Browser->append("<img src=./images/14.pgm>");

    //mat数组用来存放读取进来的所有图片的数据，其中mat的每一列对应1张图片，该实现在下面的for函数中
    Mat mat(total, src.size(), CV_32FC1);
    for(int i = 0; i < src.size(); i++)
    {
        Mat col_tmp = mat.col(i);
        src[i].reshape(1, total).col(0).convertTo(col_tmp, CV_32FC1, 1/255.);
    }
    int number_principal_compent = 12;//保留最大的主成分数
    //构造pca数据结构
    PCA pca(mat, Mat(), CV_PCA_DATA_AS_COL, number_principal_compent);
    //pca.eigenvectors中的每一行代表输入数据协方差矩阵一个特征向量，且是按照该协方差矩阵的特征值进行排序的
    pca_face1 = normalize(pca.eigenvectors.row(0)).reshape(1, src[0].rows);//第一个主成分脸
    imwrite("./result/pca_face1.jpg", pca_face1);//显示主成分特征脸1
    ui->face7Browser->append("<img src=./result/pca_face1.jpg>");

    pca_face2 = normalize(pca.eigenvectors.row(1)).reshape(1, src[0].rows);//第二个主成分脸
    imwrite("./result/pca_face2.jpg", pca_face2);//显示主成分特征脸2
    ui->face8Browser->append("<img src=./result/pca_face2.jpg>");

    pca_face3 = normalize(pca.eigenvectors.row(2)).reshape(1, src[0].rows);//第三个主成分脸
    imwrite("./result/pca_face3.jpg", pca_face3);//显示主成分特征脸3
    ui->face9Browser->append("<img src=./result/pca_face3.jpg>");

    //将原始数据通过PCA方向投影，即通过特征向量的前面几个作用后的数据，因此这里的dst的尺寸变小了
    dst = pca.project(mat);
    //通过方向投影重构原始人脸图像(其本质暂时还没完全弄明白)
    project_face1 = normalize(pca.backProject(dst).col(0)).reshape(1, src[0].rows);
    imwrite("./result/project_face1.jpg", project_face1);
    ui->face4Browser->append("<img src=./result/project_face1.jpg>");

    project_face2 = normalize(pca.backProject(dst).col(6)).reshape(1, src[0].rows);
    imwrite("./result/project_face2.jpg", project_face2);
    ui->face5Browser->append("<img src=./result/project_face2.jpg>");

    project_face3 = normalize(pca.backProject(dst).col(13)).reshape(1, src[0].rows);
    imwrite("./result/project_face3.jpg", project_face3);
    ui->face6Browser->append("<img src=./result/project_face3.jpg>");
}

void PCAFace::on_closeButton_clicked()
{
    close();
}

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

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    PCAFace w;
    w.show();
    
    return a.exec();
}