参考链接

opencv4.0 中文文档 https://apachecn.github.io/opencv-doc-zh/#/docs/4.0.0/7.1-tutorial_py_calibration 使用的是python版本

原文档https://docs.opencv.org/4.x/d4/d94/tutorial_camera_calibration.html

http://t.csdnimg.cn/HKECW

标定

棋盘https://docs.opencv.org/4.x/pattern.png

程序

#include <opencv2/opencv.hpp>
#include <stdio.h>
#include <iostream>

using namespace std;
using namespace cv;

// Defining the dimensions of checkerboard
// 定义棋盘格的尺寸
int CHECKERBOARD[2] {6,9};

int main()
{
	// Creating vector to store vectors of 3D points for each checkerboard image
	// 创建矢量以存储每个棋盘图像的三维点矢量
	std::vector<std::vector<cv::Point3f> > objpoints;

	// Creating vector to store vectors of 2D points for each checkerboard image
	// 创建矢量以存储每个棋盘图像的二维点矢量
	std::vector<std::vector<cv::Point2f> > imgpoints;

	// Defining the world coordinates for 3D points
	// 为三维点定义世界坐标系
	std::vector<cv::Point3f> objp;
	for (int i{ 0 }; i < CHECKERBOARD[1]; i++)
	{
		for (int j{ 0 }; j < CHECKERBOARD[0]; j++)
		{
			objp.push_back(cv::Point3f(j, i, 0));
		}
	}

	// Extracting path of individual image stored in a given directory
	// 提取存储在给定目录中的单个图像的路径
	std::vector<cv::String> images;

	// Path of the folder containing checkerboard images
	// 包含棋盘图像的文件夹的路径
	std::string path = "../images/CameraCalibration/*.jpg";

	// 使用glob函数读取所有图像的路径
	cv::glob(path, images);
	cout << images[0] << endl;
	cv::Mat frame, gray;
	// vector to store the pixel coordinates of detected checker board corners
	// 存储检测到的棋盘转角像素坐标的矢量
	std::vector<cv::Point2f> corner_pts;
	bool success;

	frame = cv::imread(images[0]);
	cv::cvtColor(frame,gray,cv::COLOR_BGR2GRAY);

	// Looping over all the images in the directory
	// 循环读取图像
	for (int i{ 0 }; i < images.size(); i++)
	{
		frame = cv::imread(images[i]);
		if (frame.empty())
		{
			continue;
		}
		if (i == 40)
		{
			int b = 1;
		}
		cout << "the current image is " << i << "th" << endl;
		cv::cvtColor(frame, gray, cv::COLOR_BGR2GRAY);       // COLOR_BGR2GRAY 从BGR 转换到灰度图
		cv::resize(gray, gray, cv::Size(), 0.125, 0.125, cv::INTER_LINEAR);
		cv::imshow("gray", gray);
		cv::waitKey(1);
		// Finding checker board corners
		// 寻找角点
		// If desired number of corners are found in the image then success = true
		// 如果在图像中找到所需数量的角，则success = true
		// opencv4以下版本，flag参数为CV_CALIB_CB_ADAPTIVE_THRESH | CV_CALIB_CB_FAST_CHECK | CV_CALIB_CB_NORMALIZE_IMAGE
		success = cv::findChessboardCorners(gray, cv::Size(CHECKERBOARD[0], CHECKERBOARD[1]), corner_pts, CALIB_CB_ADAPTIVE_THRESH | CALIB_CB_FAST_CHECK | CALIB_CB_NORMALIZE_IMAGE);

		/*
		 * If desired number of corner are detected,
		 * we refine the pixel coordinates and display
		 * them on the images of checker board
		*/
		// 如果检测到所需数量的角点，我们将细化像素坐标并将其显示在棋盘图像上
		if (success)
		{
			// 如果是OpenCV4以下版本，第一个参数为CV_TERMCRIT_EPS | CV_TERMCRIT_ITER
			cv::TermCriteria criteria(TermCriteria::EPS | TermCriteria::Type::MAX_ITER, 30, 0.001);

			// refining pixel coordinates for given 2d points.
			// 为给定的二维点细化像素坐标
			cv::cornerSubPix(gray, corner_pts, cv::Size(11, 11), cv::Size(-1, -1), criteria);

			// Displaying the detected corner points on the checker board
			// 在棋盘上显示检测到的角点
			cv::drawChessboardCorners(frame, cv::Size(CHECKERBOARD[0], CHECKERBOARD[1]), corner_pts, success);

			objpoints.push_back(objp);
			imgpoints.push_back(corner_pts);
		}

		//cv::imshow("Image", frame);
		//cv::waitKey(0);
	}

	cv::destroyAllWindows();

	cv::Mat cameraMatrix, distCoeffs, R, T;

	/*
	 * Performing camera calibration by
	 * passing the value of known 3D points (objpoints)
	 * and corresponding pixel coordinates of the
	 * detected corners (imgpoints)
	*/
	// 通过传递已知3D点（objpoints）的值和检测到的角点（imgpoints）的相应像素坐标来执行相机校准
	cv::calibrateCamera(objpoints, imgpoints, cv::Size(gray.rows, gray.cols), cameraMatrix, distCoeffs, R, T);

	// 内参矩阵
	std::cout << "cameraMatrix : " << cameraMatrix << std::endl;
	// 透镜畸变系数
	std::cout << "distCoeffs : " << distCoeffs << std::endl;
	// rvecs
	std::cout << "Rotation vector : " << R << std::endl;
	// tvecs
	std::cout << "Translation vector : " << T << std::endl;

	return 0;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)
project(CameraCalibration)

set(CMAKE_BUILD_TYPE "Debug")
set(CMAKE_CXX_FLAGS "-std=c++11")
set(LIBRARY_OUTPUT_PATH ${PROJECT_NAME_DIR}/lib)

find_package(OpenCV 4.0 REQUIRED)
include_directories(${OpenCV_INCLUDE_DIR})
include_directories(${PROJECT_NAME_DIR}/include)
add_subdirectory(${PROJECT_SOURCE_DIR}/src)

add_executable(CameraCalibration src/camera_calibration.cpp)
target_link_libraries(CameraCalibration ${OpenCV_LIBS})

结果

报错，

terminate called after throwing an instance of 'cv::Exception'
  what():  OpenCV(4.2.0) ../modules/calib3d/src/calibration.cpp:3681: error: (-215:Assertion failed) nimages > 0 in function 'calibrateCameraRO'

不知道为啥，

猜测是因为ipone拍摄的相机像素太高，减小尺寸试试

在for循环中加入

		cv::resize(gray, gray, cv::Size(), 0.125, 0.125, cv::INTER_LINEAR);

可以出结果了