根据人脸关键点实现平面三角剖分和最近邻搜索 ( KNN, K=1 ), opencv3.4.2, C++

头文件:

#pragma once
#include <iostream>
#include <vector>
#include <map>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>

#define UL unsigend long



using namespace std;
using namespace cv;


int test_triangulation();

void show_a_image_mat(const Mat& img);

cv::Mat VisualizePoints(const cv::Mat& src_img, const vector<cv::Point2f>& pts);

源文件：

#include "delaunay_triangulation.h"


void show_a_image_mat(const Mat& img){
    namedWindow("src_img", WINDOW_AUTOSIZE);
    imshow("src_img", img);
    waitKey();
    destroyAllWindows();
}


Mat VisualizePoints(const Mat& src_img, const vector<Point2f>& pts)
{
    // draw circles on Mat
    Mat render = src_img.clone();
    for (auto& i: pts) {
        circle(render, i, 2, Scalar(255, 255, 255), -1, CV_AA);
    }
    return render;
}


int test_triangulation(){
    cout << "start test_triangulation" << endl;

    // 读图
    string src_img_path = "/Users/liujiashu/CLionProjects/debug_lrn/jpegs/JJY.jpg";
    Mat src_img = imread(src_img_path);
    if(src_img.empty()){
        cout << "empty img" << endl;
        return -1;
    }
    auto img_height = src_img.size[0];
    auto img_width = src_img.size[1];

    // 选取一些点
    vector<Point2f> pts_vec;
    vector<int> pts_index_vec;
    map<int, int> pt_id2pt_index;

    int pt_index = 0;
    for (int i = 0; i < 20; i++) {
        for (int j = 0; j < 20; j++ ){
            pts_vec.emplace_back(img_width / 20.0 * i, img_height / 20.0 * j);
            pts_index_vec.emplace_back(pt_index);
            pt_index++;
        }
    }


    CvRect rect = {0, 0, img_width, img_height};
    Subdiv2D sub_div;
    sub_div.initDelaunay(rect);

    for(int i = 0; i < pts_vec.size(); i++) {
        int pt_id = sub_div.insert(pts_vec[i]);
        pt_index = pts_index_vec[i];
        pt_id2pt_index.insert(pair<int, int>(pt_id, pt_index));
    }


    Point2f target = {50, 50};

    auto vertex_ptr = sub_div.findNearest(target);
    auto nearest_point_cord = sub_div.getVertex(vertex_ptr);

    cout << nearest_point_cord.x << endl;
    cout << nearest_point_cord.y << endl;
    cout << pt_id2pt_index[vertex_ptr] << endl;




    if(true){
        Mat render = src_img.clone();
        for (auto& i: pts_vec) {
            circle(render, i, 2, Scalar(255, 255, 255), -1, CV_AA);
        }
        circle(render, target, 2, Scalar(0, 0, 255), -1, CV_AA);
        circle(render, nearest_point_cord, 5, Scalar(0, 255, 0), -1, CV_AA);
        show_a_image_mat(render);
    }


    return 0;
}