03-去畸变(矫正)¶

remap¶

读取相机矩阵、畸变系数

// 读取相机矩阵、畸变系数
cv::FileStorage fs("./calibration_in_params.yml", FileStorage::READ);
int image_width{0}, image_height{0};
fs["image_width"] >> image_width;
fs["image_height"] >> image_height;
Size image_size = Size(image_width, image_height);

Mat intrinsic_matrix, distortion_coeffs;
fs["cameraMatrix"] >> intrinsic_matrix;
fs["distCoeffs"] >> distortion_coeffs;
fs.release();
std::cout << intrinsic_matrix << std::endl;
std::cout << distortion_coeffs << std::endl;
std::cout << image_size << std::endl;

初始化去畸变纠正变换Map

// 初始化去畸变纠正变换Map
Mat map1, map2;
initUndistortRectifyMap(intrinsic_matrix, distortion_coeffs, Mat(),
                        intrinsic_matrix, image_size, CV_16SC2, map1, map2);

显示原图和去畸变后的图

 cv::VideoCapture capture(0);
if (!capture.isOpened()) {
    cout << "\nCouldn't open the camera\n";
    return -1;
}
// 显示原图和去畸变后的图
while (true) {
    Mat image, image0;
    capture >> image0;

    if (image0.empty()) {
        break;
    }
    // 执行映射转换
    remap(image0, image, map1, map2,
          cv::INTER_LINEAR, cv::BORDER_CONSTANT, cv::Scalar());

    imshow("original", image0);
    imshow("undistorted", image);

    if ((waitKey(30) & 255) == 27) {
        break;
    }
}

undistort¶

有时，我们只需要对一张图像进行去畸变，则可以使用更简洁的cv::undistort()函数，可以更方便的计算映射关系病将之应用于单个图像。

void undistort( 
    InputArray src,         // 输入图像
    OutputArray dst,        // 校正后的图像
    InputArray cameraMatrix,// 标定矩阵
    InputArray distCoeffs,  // 畸变系数
    InputArray newCameraMatrix = noArray() // 额外的偏移缩放矩阵
);

范例：

#include <iostream>
#include <opencv2/opencv.hpp>
#include <opencv2/imgproc.hpp>

using namespace cv;
using namespace std;

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

    // 读取相机矩阵、畸变系数
    cv::FileStorage fs("./calibration_in_params.yml", FileStorage::READ);
    int image_width{0}, image_height{0};
    fs["image_width"] >> image_width;
    fs["image_height"] >> image_height;
    Size image_size = Size(image_width, image_height);

    Mat intrinsic_matrix, distortion_coeffs;
    fs["cameraMatrix"] >> intrinsic_matrix;
    fs["distCoeffs"] >> distortion_coeffs;
    fs.release();
    std::cout << intrinsic_matrix << std::endl;
    std::cout << distortion_coeffs << std::endl;
    std::cout << image_size << std::endl;

    const Mat &image0 = imread("./calib_chess_img/image_0.jpg", IMREAD_COLOR);
    Mat image;

    undistort(image0, image, intrinsic_matrix, distortion_coeffs);

    imshow("original", image0);
    imshow("undistorted", image);

    waitKey();
    return 0;
}