OpenCV calibrateCamera（）断言失败 [英] OpenCV calibrateCamera() Assertion failed

问题描述

我一直在尝试使用Opencv calibrateCamera（）函数校准我的相机。我已经遵循在opencv示例程序中描述的相同的过程。我试图先加载10 9 x 6棋盘图像。然后找到棋盘角。如果发现角，则将角的像素位置存储在向量<载体， Point2f >> ImagePoints。对所有图像执行此操作后，将执行runCalibrationAndSave部分。在runCalibrationAndSave中，执行第一个runCalibration部分，其中用角落的实坐标值填充对象点（类型向量<向量<向量>）
。直到这一点代码工作得很好，没有问题发生。棋盘角精确找到，ImagePoints向量也用向量填充。但是当它去校准Camera（）部分OpenCV :: assertion失败，并出现以下错误：

I have been trying to calibrate my camera quite for a while using Opencv calibrateCamera() function. I have followed the same procedure as described in opencv sample program. I am trying to first load 10 9 x 6 chessboard images. Then finding chessboard corners. If corners are found then corners' pixel location is stored in vector< vector < Point2f>> ImagePoints. After doing this for all images, runCalibrationAndSave part is executed. In runCalibrationAndSave , first runCalibration part is executed where ObjectPoints (of type vector< vector < Point3f>>) are filled with corners' real coordinate values. Upto this point code works well and no problem occurs.Chessboard corners are accurately found and ImagePoints vector is also filled with vectors. But when it goes to calibrateCamera() part OpenCV:: assertion is failed with following error:

OpenCV错误：

声明失败（nimages> 0& nimages ==（int）imagePoints1.total（）
&&（！imgPtMat2 || nimages ==（int）imagePoints2 .total（）））in
collectCalibrationData，file
/ ans..../modules/calib3d/src/calibration.cpp，line 3164

Assertion failed (nimages > 0 && nimages == (int)imagePoints1.total() && (!imgPtMat2 || nimages == (int)imagePoints2.total())) in collectCalibrationData, file /............/modules/calib3d/src/calibration.cpp, line 3164

我对同样的问题做了一些研究，发现这个问题通常发生在当ObjectPoints向量和ImagePoints向量长度不相等或者没有正确填充。但在我的情况下，我已经检查调试模式，两个向量正确填充相等的长度。
对于引用，我附上了在calibrateCamera（）部分之前正确运行的代码部分，然后断言失败。

I did some research for the same problem and found that this problem usually occurs when ObjectPoints vector and ImagePoints vector are not of equal length or if they are not properly filled. But In my case I have checked in debugging mode that both vectors are properly filled with equal lengths. For the reference I have attached the code part which properly runs upto before calibrateCamera() part and then assertion is failed.

#include <iostream>
#include <sstream>
#include <time.h>
#include <stdio.h>

#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/calib3d/calib3d.hpp>
#include <opencv2/highgui/highgui.hpp>


using namespace cv;
using namespace std;
class Settings
{public:
Size boardSize;            
float squareSize;          


};
bool runCalibrationAndSave(Settings& s, Size imageSize, Mat&  cameraMatrix, Mat& distCoeffs,
                       vector<vector<Point2f> > imagePoints );

int main()
{
Settings s;
s.boardSize.width =9;
s.boardSize.height=6;
s.squareSize=50;
  Mat cameraMatrix, distCoeffs;
Size imageSize;
char filename[512];
vector<vector<Point2f> > imagePoints;
for(int counter=0; counter<10; counter++)        
{sprintf( filename, "chessboard%d.jpg", counter );

IplImage* img = cvLoadImage(filename);


 cv::Mat& m = cv::cvarrToMat(img);

Mat pointBuf = Mat::zeros(54,2,CV_32FC1);
vector<Point2f> pointBuf_vec;

bool found=false;


found = findChessboardCorners( m,s.boardSize, pointBuf,CV_CALIB_CB_ADAPTIVE_THRESH |    CV_CALIB_CB_FAST_CHECK | CV_CALIB_CB_NORMALIZE_IMAGE);
if(found)
{
cout<<"check"<<endl;
Mat viewGray;
                cvtColor(m, viewGray, CV_BGR2GRAY);
                cornerSubPix( viewGray, pointBuf, Size(11    ,11),Size(-1,-1),         TermCriteria( CV_TERMCRIT_EPS+CV_TERMCRIT_ITER, 30, 0.1 ));
 drawChessboardCorners( m, s.boardSize, Mat(pointBuf), found );


pointBuf_vec.clear();

 for(int i=0;i<54;i++)
 {
 Point2f temp;
 temp.x=pointBuf.at<float>(i,0);
 temp.y=pointBuf.at<float>(i,1);
 pointBuf_vec.push_back(temp);

 }

 imagePoints.push_back(pointBuf_vec);




}


imshow("Example1",m);
cvWaitKey(); 

imageSize = m.size();
}
runCalibrationAndSave(s, imageSize,  cameraMatrix, distCoeffs, imagePoints);
return 0;


}



static void calcBoardCornerPositions(Size boardSize, float squareSize,     vector<Point3f>& corners)

{
corners.clear();

    for( int i = 0; i < boardSize.height; i++ )
        for( int j = 0; j < boardSize.width; j++ )
           { corners.push_back(Point3f(float( j*squareSize ), float( i*squareSize ), 0));

        }

}

 static bool runCalibration( Settings& s, Size& imageSize, Mat& cameraMatrix, Mat&   distCoeffs,
                        vector<vector<Point2f> > imagePoints, vector<Mat>& rvecs,   vector<Mat>& tvecs,
                        vector<float>& reprojErrs,  double& totalAvgErr)

 {

cameraMatrix = Mat::eye(3, 3, CV_64F);
 //   if( s.flag & CV_CALIB_FIX_ASPECT_RATIO )
 //      cameraMatrix.at<double>(0,0) = 1.0;

  distCoeffs = Mat::zeros(8, 1, CV_64F);

  vector<vector<Point3f> > objectPoints;
  Mat object_pointBuf = Mat::zeros(s.boardSize.width*s.boardSize.height,3,CV_32FC1);
    vector<Point3f> object_pointBuf_vec;

  calcBoardCornerPositions(s.boardSize, s.squareSize, object_pointBuf_vec);
  for(int k=0;k<imagePoints.size();k++)
  {
    objectPoints.push_back(object_pointBuf_vec);
  }





 // objectPoints.resize(imagePoints.size(),objectPoints[0]);

  //Find intrinsic and extrinsic camera parameters
  double rms = calibrateCamera(objectPoints, imagePoints, imageSize, cameraMatrix,
                             distCoeffs, rvecs, tvecs, /*s.flag|*  /CV_CALIB_FIX_K4|CV_CALIB_FIX_K5);

  cout << "Re-projection error reported by calibrateCamera: "<< rms << endl;

  bool ok = checkRange(cameraMatrix) && checkRange(distCoeffs);

 //   totalAvgErr = computeReprojectionErrors(objectPoints, imagePoints,
                                  //       rvecs, tvecs, cameraMatrix, distCoeffs,   reprojErrs);

  return ok;
}



bool runCalibrationAndSave(Settings& s, Size imageSize, Mat&  cameraMatrix, Mat&     distCoeffs,vector<vector<Point2f> > imagePoints )

{
vector<Mat> rvecs, tvecs;
vector<float> reprojErrs;
double totalAvgErr = 0;

 bool ok = runCalibration(s,imageSize, cameraMatrix, distCoeffs, imagePoints, rvecs,   tvecs,
                         reprojErrs, totalAvgErr);
  cout << (ok ? "Calibration succeeded" : "Calibration failed")
    << ". avg re projection error = "  << totalAvgErr ;


 return ok;
} 

我使用Visual C ++和Opencv 2.4.9。请帮我找出问题。这是我第一次在SO问任何问题，请让我知道，如果我在提出问题时犯了任何错误。感谢您的帮助。

I am using Visual C++ and Opencv 2.4.9. Please help me in figuring out the problem. This is first time I am asking any question in SO , please let me know if I made any mistake in asking question. Thanks for help in advance.

推荐答案

我发现要解决这个问题的唯一方法是下载OpenCV源代码，然后使用CMAKE和Visual Studio 2010构建它。现在使用cmake构建的库，消除所有这些问题。还有imread和imshow相关的问题;那些问题也不会出现，当你从CMAKE构建openCV库。
如何从CMAKE构建库检查此链接
http://docs.opencv.org/doc/tutorials/introduction/windows_install/windows_install.html
我希望它会有所帮助。

The only way which I found to tackle with this problem was to download OpenCV source code and then build it using CMAKE and Visual Studio 2010. Now using cmake built libraries, eliminate all of these problems. There have also been 'imread' and 'imshow' related problems; those problems also don't appear, when you build openCV libraries from CMAKE. For how to build libraries from CMAKE check this link http://docs.opencv.org/doc/tutorials/introduction/windows_install/windows_install.html I hope it would help.

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