源码位置：https://github.com/comhaqs/face_find.git  分支： develop_face_recognition

opencv的人脸识别模块现在是放在另外一个库opencv_contrib里，需要编译到opencv里才可以使用，故这里将opencv和opencv_contrib的源码都下下来，opencv源码:https://github.com/opencv/opencv/releases ，opencv_contrib源码:https://github.com/opencv/opencv_contrib/releases。两个的版本要一致，例如都是4.2.0。下好后，我这边是使用cmake的gui版本，cmake的源码目录指向opencv的源码目录，输出文件目录最好指向一个空文件夹，然后点击Configure按钮，变量区会有很多红色定义，在变量区中找到OPENCV_EXTRA_MODULES_PATH，将其选择为opencv_contrib/modules目录，并勾选BUILD_opencv_world，再点击configure。直到变量区没有红色，然后点击Generate按钮生成VS项目文件。

生成项目文件后，使用对应的VS打开，然后选择opencv_world工程编译即可，因为是人脸识别，所以还需要将opencv_contrib\modules\face\include下的opencv文件夹合并到程序的include目录里。编译的时候可能会提示部分文件丢失，需要手动下载，官方的issues里有人提到了这个问题（https://github.com/opencv/opencv_contrib/issues/1301），下面有人给出了对应的下载路径。将url显示的内容另存为对应的文件，放到opencv_contrib\modules\xfeatures2d\src目录下即可。其实上面输出文件夹CMakeDownloadLog.txt里已经记录了对应的下载路径。下载时会碰到无法打开url的问题，多刷新几次就可以了。也可以直接从CSDN下载：https://download.csdn.net/download/comhaqs/12088222

Hi! The solution I used was to download by hand all the missing files, so if you encounter the same issue please use the folliwing command in a bash file:#!/bin/bash
cd ./cache/xfeatures2d/
cd boostdesccurl https://raw.githubusercontent.com/opencv/opencv_3rdparty/34e4206aef44d50e6bbcd0ab06354b52e7466d26/boostdesc_lbgm.i > 0ae0675534aa318d9668f2a179c2a052-boostdesc_lbgm.i
curl https://raw.githubusercontent.com/opencv/opencv_3rdparty/34e4206aef44d50e6bbcd0ab06354b52e7466d26/boostdesc_binboost_256.i > e6dcfa9f647779eb1ce446a8d759b6ea-boostdesc_binboost_256.i
curl https://raw.githubusercontent.com/opencv/opencv_3rdparty/34e4206aef44d50e6bbcd0ab06354b52e7466d26/boostdesc_binboost_128.i > 98ea99d399965c03d555cef3ea502a0b-boostdesc_binboost_128.i
curl https://raw.githubusercontent.com/opencv/opencv_3rdparty/34e4206aef44d50e6bbcd0ab06354b52e7466d26/boostdesc_binboost_064.i > 202e1b3e9fec871b04da31f7f016679f-boostdesc_binboost_064.i
curl https://raw.githubusercontent.com/opencv/opencv_3rdparty/34e4206aef44d50e6bbcd0ab06354b52e7466d26/boostdesc_bgm_hd.i > 324426a24fa56ad9c5b8e3e0b3e5303e-boostdesc_bgm_hd.i
curl https://raw.githubusercontent.com/opencv/opencv_3rdparty/34e4206aef44d50e6bbcd0ab06354b52e7466d26/boostdesc_bgm_bi.i > 232c966b13651bd0e46a1497b0852191-boostdesc_bgm_bi.i
curl https://raw.githubusercontent.com/opencv/opencv_3rdparty/34e4206aef44d50e6bbcd0ab06354b52e7466d26/boostdesc_bgm.i > 0ea90e7a8f3f7876d450e4149c97c74f-boostdesc_bgm.i
cd ../vgg
curl https://raw.githubusercontent.com/opencv/opencv_3rdparty/fccf7cd6a4b12079f73bbfb21745f9babcd4eb1d/vgg_generated_120.i > 151805e03568c9f490a5e3a872777b75-vgg_generated_120.i
curl https://raw.githubusercontent.com/opencv/opencv_3rdparty/fccf7cd6a4b12079f73bbfb21745f9babcd4eb1d/vgg_generated_64.i > 7126a5d9a8884ebca5aea5d63d677225-vgg_generated_64.i
curl https://raw.githubusercontent.com/opencv/opencv_3rdparty/fccf7cd6a4b12079f73bbfb21745f9babcd4eb1d/vgg_generated_48.i > e8d0dcd54d1bcfdc29203d011a797179-vgg_generated_48.i
curl https://raw.githubusercontent.com/opencv/opencv_3rdparty/fccf7cd6a4b12079f73bbfb21745f9babcd4eb1d/vgg_generated_80.i > 7cd47228edec52b6d82f46511af325c5-vgg_generated_80.iAnd then run cmake again, and make. Hope this help

 

人脸识别类的代码如下：

#include "face_recognition.h"
#include <opencv2/opencv.hpp>#include <boost/filesystem.hpp>
#include <boost/format.hpp>using namespace cv;
using namespace cv::face;face_recognition::face_recognition()
{}void face_recognition::start(){try{Ptr<LBPHFaceRecognizer> p_model = LBPHFaceRecognizer::create();// 获取训练图片集合std::vector<info_recognition_ptr> infos;if(!find_face_info(infos, "./face")){return;}std::vector<Mat> images;std::vector<int> labels;for(auto& p_info : infos){for(auto& f : p_info->files){// 这里记得是IMREAD_GRAYSCALE，即灰度图片，不然会报错images.push_back(imread(f, cv::IMREAD_GRAYSCALE));labels.push_back(p_info->index);}m_index_to_name.insert(std::make_pair(p_info->index, p_info->name));}// 训练模型p_model->train(images, labels);mp_model = p_model;// 加载opencv提供的人脸检测模型，识别率比较低std::string face_file("./haarcascade_frontalface_alt2.xml");if(boost::filesystem::exists(face_file)){mp_cascade = std::make_shared<cv::CascadeClassifier>();mp_cascade->load(face_file);}else{LOG_ERROR("找不到对应的文件检测模型文件:"<<face_file);}}catch(const std::exception& e){LOG_ERROR("发生错误:"<<e.what());}
}bool face_recognition::train(unsigned char *p_data, int width, int height){try {if(!mp_model || !mp_cascade){return false;}// 原始图片数据转成灰度图片cv::Mat bgr(cv::Size(width, height), CV_8UC3);bgr.data = p_data;cv::Mat gray;gray.create(bgr.size(), bgr.type());cv::cvtColor(bgr, gray, cv::COLOR_BGR2GRAY);// 先人脸检测，再人脸识别std::vector<cv::Rect> rect;mp_cascade->detectMultiScale(gray, rect, 1.1, 3, 0);for (auto& r : rect){bool flag_find_face = false;std::string name;// 复制出检测出来的人脸，然后转换成灰度图片，不转换会报错cv::Mat desc;bgr(r).copyTo(desc);cv::Mat gray_desc;gray_desc.create(desc.size(), desc.type());cv::cvtColor(desc, gray_desc, cv::COLOR_BGR2GRAY);int index = -1;double confidence = 0.0;// 实际总会返回一个检测结果，置信度暂时不知道怎么使用mp_model->predict(gray_desc, index, confidence);if(0 > index){}else{auto iter = m_index_to_name.find(index);if(m_index_to_name.end() == iter){LOG_WARN("找不到对应人脸信息；序号:"<<index);}else{LOG_INFO("找到人脸；名称:"<<iter->second<<"; 可信度:"<<confidence<<"; 序号:"<<index);name = iter->second;flag_find_face = true;}}if(flag_find_face){cv::rectangle(bgr, r, CV_RGB(0, 255, 0), 4);cv::putText(bgr, name, Point(r.x + 0.5 * r.width, r.y - 5), cv::FONT_HERSHEY_COMPLEX_SMALL, 1, CV_RGB(0, 255, 0));}else{cv::rectangle(bgr, r, CV_RGB(255, 0, 0), 2);}}} catch(const std::exception& e){LOG_ERROR("发生错误:"<<e.what());}return true;
}bool face_recognition::find_and_save_face(const std::string& folder_desc, const std::string& folder_src){std::vector<std::string> files;if(!find_file_from_folder(files, folder_src)){return false;}cv::CascadeClassifier cascade;cascade.load("./haarcascade_frontalface_alt2.xml");for(auto& p : files){cv::Mat src = cv::imread(p);if(nullptr == src.data){LOG_ERROR("文件无法正常读取:"<<p);continue;}cv::Mat gray;gray.create(src.size(), src.type());cv::cvtColor(src, gray, cv::COLOR_BGR2GRAY);// 人脸检测std::vector<cv::Rect> rect;cascade.detectMultiScale(gray, rect, 1.1, 3, 0);if(rect.empty()){LOG_WARN("没有检测到人脸:"<<p);continue;}int index = 0;for (auto& r : rect){cv::Mat desc;src(r).copyTo(desc);imwrite((boost::format("%s/%d.png") % folder_desc % (index++)).str(), desc);}}return true;
}
bool face_recognition::find_face_info(std::vector<info_recognition_ptr>& infos, const std::string& folder){std::vector<std::string> all_folders;if(!find_folder_from_folder(all_folders, boost::filesystem::system_complete(folder).string())){return false;}int index = 1;for(auto& d : all_folders){std::vector<std::string> files;if (!find_file_from_folder(files, d)) {continue;}auto path = boost::filesystem::system_complete(d);auto parent_folder = path.parent_path().string();auto name = path.string().substr(parent_folder.size() + 1);auto p_info = std::make_shared<info_recognition>();p_info->index = index++;p_info->name = name;for(auto& f : files){p_info->files.push_back(f);}infos.push_back(p_info);}return true;
}bool face_recognition::find_file_from_folder(std::vector<std::string>& files, const std::string& folder, const std::string& extend){boost::filesystem::path path_folder(folder);if(!boost::filesystem::exists(path_folder)){LOG_ERROR("文件夹路径不存在:"<<folder);return false;}boost::filesystem::directory_iterator end;for(boost::filesystem::directory_iterator iter(path_folder); iter != end; ++iter){auto path = iter->path();if (boost::filesystem::is_directory(path)) {continue;}if(!extend.empty() && extend != path.extension()){continue;}files.push_back(path.string());}return true;
}bool face_recognition::find_folder_from_folder(std::vector<std::string>& all_folders, const std::string& folder){boost::filesystem::path path_folder(folder);if(!boost::filesystem::exists(path_folder)){LOG_ERROR("文件夹路径不存在:"<<folder);return false;}boost::filesystem::directory_iterator end;for(boost::filesystem::directory_iterator iter(path_folder); iter != end; ++iter){auto path = iter->path();if (!boost::filesystem::is_directory(path)) {continue;}if("." == path.string() || ".." == path.string()){continue;}all_folders.push_back(path.string());}return true;
}