使用OpenCV进行相机校准 - findChessboardCorners返回false

时间:2014-12-07 21:37:12

标签: c++ opencv camera-calibration

我尝试校准相机。我举了一些例子,但他们都没有找到棋盘的角落。最后,我使用this question的代码,但找不到角落。下面是一张图片。我用它来寻找角落。

我在网上找到了这个问题的命令。它说 board_sz必须保持内角的数量,而不是 的正方形数。 board_sz是一个二维对象。我不明白我怎么能用它来保存除了h * w之外的内角数。

我给w = 9,h = 7

编辑1 ** **代码:

#include <cv.h>
#include <highgui.h>
#include <vector>
#include <stdlib.h>
#include <stdio.h>

using namespace cv;
using namespace std;

int main()
{
int numBoards = 0;
int numCornersHor;
int numCornersVer;

printf("Enter number of corners along width: ");
scanf("%d", &numCornersHor);

printf("Enter number of corners along height: ");
scanf("%d", &numCornersVer);

printf("Enter number of boards: ");
scanf("%d", &numBoards);

int numSquares = numCornersHor * numCornersVer;
Size board_sz = Size(numCornersHor, numCornersVer);
VideoCapture capture = VideoCapture(0);

vector<vector<Point3d>> object_points;
vector<vector<Point2d>> image_points;

vector<Point2d> corners;
int successes=0;

Mat image;
Mat gray_image;
capture >> image;

vector<Point3d> obj;
for(int j=0;j<numSquares;j++)
    obj.push_back(Point3d(j/numCornersHor, j%numCornersHor, 0.0f));

while(successes<numBoards)
{
    cvtColor(image, gray_image, CV_BGR2GRAY);

    bool found = findChessboardCorners(image, board_sz, corners, CV_CALIB_CB_ADAPTIVE_THRESH | CV_CALIB_CB_FILTER_QUADS);

    if(found)
    {
        cornerSubPix(gray_image, corners, Size(11, 11), Size(-1, -1), TermCriteria(CV_TERMCRIT_EPS | CV_TERMCRIT_ITER, 30, 0.1));
        drawChessboardCorners(gray_image, board_sz, corners, found);
    }

    imshow("win1", image);
    imshow("win2", gray_image);

    capture >> image;

    int key = waitKey(1);

    if(key==27)
        return 0;

    if(key==' ' && found!=0)
    {
        image_points.push_back(corners);
        object_points.push_back(obj);
        printf("Snap stored!\n");

        successes++;

        if(successes>=numBoards)
            break;
    }
}

Mat intrinsic = Mat(3, 3, CV_32FC1);
Mat distCoeffs;
vector<Mat> rvecs;
vector<Mat> tvecs;

intrinsic.ptr<float>(0)[0] = 1;
intrinsic.ptr<float>(1)[1] = 1;

calibrateCamera(object_points, image_points, image.size(), intrinsic, distCoeffs, rvecs, tvecs);

Mat imageUndistorted;
while(1)
{
    capture >> image;
    undistort(image, imageUndistorted, intrinsic, distCoeffs);

    imshow("win1", image);
    imshow("win2", imageUndistorted);

    waitKey(1);
}

capture.release();

return 0;
}

图片:

enter image description here

1 个答案:

答案 0 :(得分:11)

尝试尺寸(8,6)。正确计算正方形有点令人困惑,但试着计算内部&#39;角落。