use opencv to calibrate camera problem
Hi,
I am trying to write a program for fixing camera distortion. I studied the sample code from opencv and also looked at some tutorials online. However, I was having trouble with the calibrateCamera function call. The version of opencv I am using is 2.4.5.
Here is the code that I have:
#include "stdafx.h"
#include <cv.h>
#include <highgui.h>
using namespace cv;
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{
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);
/* Chessboard images that will be used to calibrate the camera */
vector<string> imageList(10);
imageList[0] = "chessboard1.jpg";
imageList[1] = "chessboard2.jpg";
imageList[2] = "chessboard3.jpg";
imageList[3] = "chessboard4.jpg";
imageList[4] = "chessboard5.jpg";
imageList[5] = "chessboard6.jpg";
imageList[6] = "chessboard7.jpg";
imageList[7] = "chessboard8.jpg";
imageList[8] = "chessboard9.jpg";
imageList[9] = "chessboard10.jpg";
/* physical position of the corners (in 3D space) */
vector<vector<Point3f>> object_points(1);
/* location of corners in the image (in 2D space) */
vector<vector<Point2f>> image_points;
/* corners in the current chessboard image */
vector<Point2f> corners;
/* ??? */
int successes = 0;
Mat image;
Mat gray_image;
for (int index = 0; index < numSquares; index++)
{
object_points[0].push_back(Point3f(float(index/numCornersHor), float(index % numCornersHor), 0.0f));
}
while(successes < numBoards)
{
image = imread(imageList[successes], CV_LOAD_IMAGE_COLOR);
/* convert image into a grayscale image */
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);
image_points.push_back(corners);
successes++;
}
}
object_points.resize(image_points.size(), object_points[0]);
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);
return 0;
}
I keep getting errors from opencv on this particular line from function collectCalibrationData:
for( i = 0; i < nimages; i++ )
{
ni = objectPoints.getMat(i).checkVector(3, CV_32F);
CV_Assert( ni >= 0 );
total += ni;
}
The program fails the assertion every single time.
I don't know what is wrong with my object_points declaration. Could anyone explain to me why and how to fix it? I have been spending a long time on this and not getting any where. Thank you very much.