使用opencv进行相机校准(断言失败故障)

Question

我试图通过使用opencv相机校准函数获得相机校准参数。我有一个视频，并试图找到校准参数，并找到视频中的点，其中包括一个在不同位置的棋盘。但是我还没有通过校准阶段。我可以找到棋盘的角落，并在openCV窗口中显示它们，但当它涉及到行:

calibrateCamera(objectPoints,imagePoints..............) 

抛出异常并停止。

我得到以下错误:OpenCV错误:断言失败0 &&nimages==int imagePoints1。总(),,下面是我的代码:

#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "C:/opencv/include/opencv/cv.h"
#include <iostream>
#include <math.h>
using namespace cv;
using namespace std;
std::vector<cv::Point2f> imageCorners;
std::vector<cv::Point3f> objectCorners;
std::vector<std::vector<cv::Point3f>> objectPoints;
std::vector<std::vector<cv::Point2f>> imagePoints;
void addPoints(const std::vector<cv::Point2f>&imageCorners, const std::vector<cv::Point3f>& objectCorners)
{
// 2D image points from one view
imagePoints.push_back(imageCorners);
// corresponding 3D scene points
objectPoints.push_back(objectCorners);
}
int main()
{
int key;
cv::Mat   image;
cv::Mat   gray_image;
VideoCapture cap("here goes path of the file"); 
   if (!cap.isOpened())  // check if we succeeded
       cout<<"failed";
else
   cout<<"success";
    cvNamedWindow( "video",0);
cv::Size boardSize(8,6);
// output Matrices
cv::Mat cameraMatrix;
std::vector<cv::Mat> rvecs, tvecs;
cv::Mat distCoeffs;
for (int i=0; i<boardSize.height; i++) 
{
    for (int j=0; j<boardSize.width; j++) 
    {
        objectCorners.push_back(cv::Point3f(i, j, 0.0f));
    }
}
int frame=1;
int corner_count=0;
while(1) 
{
    if(cap.read(image))
    {
        frame++;
        if(frame%20==0)
        {
            if(waitKey(30) >= 0) break;
            bool found = cv::findChessboardCorners(image, boardSize, imageCorners);
            cvtColor( image, gray_image, CV_RGB2GRAY );

                addPoints(imageCorners, objectCorners);
            //bool found = cv::findChessboardCorners(image,boardSize, imageCorners);
            cv::drawChessboardCorners(gray_image,boardSize, imageCorners,found);
            imshow( "video",  gray_image );
        }
    }
    else
        break;
}
int flag=0;
std::string text="";
for (int i=1; i<imagePoints.size();i++)
{
    std::stringstream out;
    out << imagePoints[i];
    text=out.str();
    cout<<text<<endl;
}
calibrateCamera(objectPoints,imagePoints,gray_image.size(), cameraMatrix, distCoeffs, rvecs, tvecs, flag);
return 0;
}

Answer 1

打印所有std::vector的大小，我怀疑您将空向量传递给该函数。

编辑:

我在这个答案中分享了一些关于如何进行相机校准的说明。这些引用包括工作源代码。你可能需要对这些程序做一个小的调整，这样它们就可以用视频来代替了。

Answer 2

你应该看看这个:http://docs.opencv.org/modules/calib3d/doc/camera_calibration_and_3d_reconstruction.html#bool findChessboardCorners(InputArray image, Size patternSize, OutputArray corners, int flags)

它说你的源棋盘视图必须是8位灰度或彩色图像。所以你必须使用这个:bool found = cv::findChessboardCorners(gray_image, boardSize, imageCorners);