原始碼：
https://github.com/raulmur/ORB_SLAM2

本人ubuntu16.04系統

1.pre

C++11.

Pangolin

https://github.com/stevenlovegrove/Pangolin
之前教程：https://blog.csdn.net/qq_45539458/article/details/106411290

OpenCV

at leat 2.4.3. Tested with OpenCV 2.4.11 and OpenCV 3.2.
檢視版本

pkg-config opencv --modversion 

Eigen3 at least 3.1.0.

檢視版本

vim /usr/local/include/eigen3/Eigen/src/Core/util

or

vim /usr/include/eigen3/Eigen/src/Core/util/Macros.h

sudo apt-get install libeigen3-dev
sudo cp -r /usr/local/include/eigen3/Eigen /usr/local/include 

3.2.92

g20，DBoW2

檢視版本

locate g2o

ros have g20，DBoW2

ros(optional)

可選
教程：
https://blog.csdn.net/qq_45539458/article/details/106456408

2.安裝編譯

cd ORB_SLAM2
chmod +x build.sh
vim build.sh
//delete -j
./build.sh

3.測試

14講作業
在CMakeLists.txt 末尾加入

#生成呼叫 myvideo.mp4 可執行檔案
add_executable(myvideo myvideo.cpp)
target_link_libraries(myvideo ${PROJECT_NAME})
#生成呼叫攝像頭可執行檔案
add_executable(myslam myslam.cpp)
target_link_libraries(myslam ${PROJECT_NAME})

將 myslam.cpp、myvideo.cpp、myslam.yaml、myvideo.mp4 放在
ORB_SLAM2/目錄下。

myslam.yaml and myvideo.yaml ：

%YAML:1.0

#--------------------------------------------------------------------------------------------
# Camera Parameters. Adjust them!
#--------------------------------------------------------------------------------------------

# Camera calibration and distortion parameters (OpenCV) 
Camera.fx: 500.0
Camera.fy: 500.0
Camera.cx: 320.0
Camera.cy: 180.0

Camera.k1: 0
Camera.k2: 0
Camera.p1: 0
Camera.p2: 0
Camera.k3: 0

# Camera frames per second 
Camera.fps: 30.0

# Color order of the images (0: BGR, 1: RGB. It is ignored if images are grayscale)
Camera.RGB: 0

#--------------------------------------------------------------------------------------------
# ORB Parameters
#--------------------------------------------------------------------------------------------

# ORB Extractor: Number of features per image
ORBextractor.nFeatures: 2000

# ORB Extractor: Scale factor between levels in the scale pyramid 	
ORBextractor.scaleFactor: 1.2

# ORB Extractor: Number of levels in the scale pyramid	
ORBextractor.nLevels: 8

# ORB Extractor: Fast threshold
# Image is divided in a grid. At each cell FAST are extracted imposing a minimum response.
# Firstly we impose iniThFAST. If no corners are detected we impose a lower value minThFAST
# You can lower these values if your images have low contrast			
ORBextractor.iniThFAST: 20
ORBextractor.minThFAST: 7

#--------------------------------------------------------------------------------------------
# Viewer Parameters
#--------------------------------------------------------------------------------------------
Viewer.KeyFrameSize: 0.05
Viewer.KeyFrameLineWidth: 1
Viewer.GraphLineWidth: 0.9
Viewer.PointSize: 2
Viewer.CameraSize: 0.08
Viewer.CameraLineWidth: 3
Viewer.ViewpointX: 0
Viewer.ViewpointY: -0.7
Viewer.ViewpointZ: -1.8
Viewer.ViewpointF: 500

myslam.cpp：

#include <opencv2/opencv.hpp>

// ORB-SLAM的系統介面
#include "System.h"

#include <string>
#include <chrono>   // for time stamp
#include <iostream>

using namespace std;

// 引數檔案與字典檔案
// 如果你係統上的路徑不同，請修改它
string parameterFile = "./myslam.yaml";
string vocFile = "./Vocabulary/ORBvoc.txt";

int main(int argc, char **argv) {

    // 宣告 ORB-SLAM2 系統
    ORB_SLAM2::System SLAM(vocFile, parameterFile, ORB_SLAM2::System::MONOCULAR, true);

    // 獲取相機影像程式碼
    cv::VideoCapture cap(0);    // change to 1 if you want to use USB camera.

    // 解析度設為640x480
    cap.set(CV_CAP_PROP_FRAME_WIDTH, 640);
    cap.set(CV_CAP_PROP_FRAME_HEIGHT, 480);

    // 記錄系統時間
    auto start = chrono::system_clock::now();

    while (1) {
        cv::Mat frame;
        cap >> frame;   // 讀取相機資料
        auto now = chrono::system_clock::now();
        auto timestamp = chrono::duration_cast<chrono::milliseconds>(now - start);
        SLAM.TrackMonocular(frame, double(timestamp.count())/1000.0);
    }

    return 0;
}

myvideo.cpp：

#include <opencv2/opencv.hpp>

// ORB-SLAM的系統介面
#include "System.h"

#include <string>
#include <chrono>   // for time stamp
#include <iostream>

using namespace std;

// 引數檔案與字典檔案
// 如果你係統上的路徑不同，請修改它
string parameterFile = "./myvideo.yaml";
string vocFile = "./Vocabulary/ORBvoc.txt";

// 視訊檔案
string videoFile = "./myvideo.mp4";

int main(int argc, char **argv) {

    // 宣告 ORB-SLAM2 系統
    ORB_SLAM2::System SLAM(vocFile, parameterFile, ORB_SLAM2::System::MONOCULAR, true);

    // 獲取視訊影像
    cv::VideoCapture cap(videoFile);    // change to 1 if you want to use USB camera.

    // 記錄系統時間
    auto start = chrono::system_clock::now();

    while (1) {
        cv::Mat frame;
        cap >> frame;   // 讀取相機資料
        if ( frame.data == nullptr )
            break;

        // rescale because image is too large
        cv::Mat frame_resized;
        cv::resize(frame, frame_resized, cv::Size(640,360));

        auto now = chrono::system_clock::now();
        auto timestamp = chrono::duration_cast<chrono::milliseconds>(now - start);
        SLAM.TrackMonocular(frame_resized, double(timestamp.count())/1000.0);
        cv::waitKey(30);
    }

    SLAM.Shutdown();
    return 0;
}

mkdir abuild
cd abuild
cmake ../
make

將 ~/ORB_SLAM2/Examples/Monocular 裡 生 成 的
myslam 複製到~/ORB_SLAM2

 ./myslam

 ./myslam