private void Calibrate(IEnumerable<Image<Gray, byte>> images, int nx, int ny, int useUncalibrated, float _squareSize /* Chessboard square size in cm */)
{
int displayCorners = 1;
int showUndistorted = 1;
bool isVerticalStereo = false;//OpenCV can handle left-right
//or up-down camera arrangements
const int maxScale = 1;
//FILE* f = fopen(imageList, "rt");
int i, j, lr, nframes, n = nx*ny, N = 0;
List<MCvPoint3D32f> objectPoints;
var points = new List<MCvPoint2D64f>[2];
List<int> npoints;
List<char>[] active = new List<char>[2];
var temp = new PointF[n];
var imageSize = new System.Drawing.Size(0,0);
// ARRAY AND VECTOR STORAGE:
Matrix<double> _M1 = new Matrix<double>(3, 3);
Matrix<double> _M2 = new Matrix<double>(3, 3);
Matrix<double> _D1 = new Matrix<double>(1, 5);
Matrix<double> _D2 = new Matrix<double>(1, 5);
Matrix<double> _R = new Matrix<double>(3, 3);
Matrix<double> _T = new Matrix<double>(3, 1);
Matrix<double> _E = new Matrix<double>(3, 3);
Matrix<double> _F = new Matrix<double>(3, 3);
Matrix<double> _Q = new Matrix<double>(4, 4);
double [,] M1 = _M1.Data;
double [,] M2 = _M2.Data;
double [,] D1 = _D1.Data;
double [,] D2 = _D2.Data;
double [,] R = _R.Data;
double [,] T = _T.Data;
double [,] E = _E.Data;
double [,] F = _F.Data;
double [,] Q = _Q.Data;
for(i=0;i<images.Count();i++)
{
int count = 0, result=0;
lr = i % 2;
List<MCvPoint2D64f> pts = points[lr];
var img = images.ElementAt(i);
imageSize = img.Size;
//FIND CHESSBOARDS AND CORNERS THEREIN:
for( int s = 1; s <= maxScale; s++ )
{
var timg = img;
if( s > 1 )
{
timg=new Image<Gray,byte>(img.Width * s, img.Height * s);
img.Resize(timg.Width, timg.Height, Emgu.CV.CvEnum.INTER.CV_INTER_CUBIC);
}
temp = Emgu.CV.CameraCalibration.FindChessboardCorners(timg, new Size(nx, ny),
Emgu.CV.CvEnum.CALIB_CB_TYPE.ADAPTIVE_THRESH | Emgu.CV.CvEnum.CALIB_CB_TYPE.NORMALIZE_IMAGE);
Emgu.CV.CameraCalibration.
result = temp.Count();
if( timg != img )
timg.Dispose();
if( result == 0 || s == maxScale)
for( j = 0; j < count; j++ )
{
temp[j].X /= s;
temp[j].Y /= s;
}
if( result )
break;
}
if( displayCorners )
{
printf("%s\n", buf);
IplImage* cimg = cvCreateImage( imageSize, 8, 3 );
cvCvtColor( img, cimg, CV_GRAY2BGR );
cvDrawChessboardCorners( cimg, cvSize(nx, ny), &temp[0],
count, result );
cvShowImage( "corners", cimg );
cvReleaseImage( &cimg );
if( cvWaitKey(0) == 27 ) //Allow ESC to quit
exit(-1);
}
else
putchar('.');
N = pts.size();
pts.resize(N + n, cvPoint2D32f(0,0));
active[lr].push_back((uchar)result);
//assert( result != 0 );
if( result )
{
//Calibration will suffer without subpixel interpolation
cvFindCornerSubPix( img, &temp[0], count,
cvSize(11, 11), cvSize(-1,-1),
cvTermCriteria(CV_TERMCRIT_ITER+CV_TERMCRIT_EPS,
30, 0.01) );
copy( temp.begin(), temp.end(), pts.begin() + N );
}
cvReleaseImage( &img );
}
fclose(f);
printf("\n");
// HARVEST CHESSBOARD 3D OBJECT POINT LIST:
nframes = active[0].size();//Number of good chessboads found
objectPoints.resize(nframes*n);
for( i = 0; i < ny; i++ )
for( j = 0; j < nx; j++ )
objectPoints[i*nx + j] = cvPoint3D32f(i*squareSize, j*squareSize, 0);
for( i = 1; i < nframes; i++ )
copy( objectPoints.begin(), objectPoints.begin() + n,
objectPoints.begin() + i*n );
npoints.resize(nframes,n);
N = nframes*n;
CvMat _objectPoints = cvMat(1, N, CV_32FC3, &objectPoints[0] );
CvMat _imagePoints1 = cvMat(1, N, CV_32FC2, &points[0][0] );
CvMat _imagePoints2 = cvMat(1, N, CV_32FC2, &points[1][0] );
CvMat _npoints = cvMat(1, npoints.size(), CV_32S, &npoints[0] );
cvSetIdentity(&_M1);
cvSetIdentity(&_M2);
cvZero(&_D1);
cvZero(&_D2);
// CALIBRATE THE STEREO CAMERAS
printf("Running stereo calibration ...");
fflush(stdout);
cvStereoCalibrate( &_objectPoints, &_imagePoints1,
&_imagePoints2, &_npoints,
&_M1, &_D1, &_M2, &_D2,
imageSize, &_R, &_T, &_E, &_F,
cvTermCriteria(CV_TERMCRIT_ITER+
CV_TERMCRIT_EPS, 100, 1e-5),
CV_CALIB_FIX_ASPECT_RATIO +
CV_CALIB_ZERO_TANGENT_DIST +
CV_CALIB_SAME_FOCAL_LENGTH );
printf(" done\n");
// CALIBRATION QUALITY CHECK
// because the output fundamental matrix implicitly
// includes all the output information,
// we can check the quality of calibration using the
// epipolar geometry constraint: m2^t*F*m1=0
vector<CvPoint3D32f> lines[2];
points[0].resize(N);
points[1].resize(N);
_imagePoints1 = cvMat(1, N, CV_32FC2, &points[0][0] );
_imagePoints2 = cvMat(1, N, CV_32FC2, &points[1][0] );
lines[0].resize(N);
lines[1].resize(N);
CvMat _L1 = cvMat(1, N, CV_32FC3, &lines[0][0]);
CvMat _L2 = cvMat(1, N, CV_32FC3, &lines[1][0]);
//Always work in undistorted space
cvUndistortPoints( &_imagePoints1, &_imagePoints1,
&_M1, &_D1, 0, &_M1 );
cvUndistortPoints( &_imagePoints2, &_imagePoints2,
&_M2, &_D2, 0, &_M2 );
cvComputeCorrespondEpilines( &_imagePoints1, 1, &_F, &_L1 );
cvComputeCorrespondEpilines( &_imagePoints2, 2, &_F, &_L2 );
double avgErr = 0;
for( i = 0; i < N; i++ )
{
double err = fabs(points[0][i].x*lines[1][i].x +
points[0][i].y*lines[1][i].y + lines[1][i].z)
+ fabs(points[1][i].x*lines[0][i].x +
points[1][i].y*lines[0][i].y + lines[0][i].z);
avgErr += err;
}
printf( "avg err = %g\n", avgErr/(nframes*n) );
//COMPUTE AND DISPLAY RECTIFICATION
if( showUndistorted )
{
CvMat* mx1 = cvCreateMat( imageSize.height,
imageSize.width, CV_32F );
CvMat* my1 = cvCreateMat( imageSize.height,
imageSize.width, CV_32F );
CvMat* mx2 = cvCreateMat( imageSize.height,
imageSize.width, CV_32F );
CvMat* my2 = cvCreateMat( imageSize.height,
imageSize.width, CV_32F );
CvMat* img1r = cvCreateMat( imageSize.height,
imageSize.width, CV_8U );
CvMat* img2r = cvCreateMat( imageSize.height,
imageSize.width, CV_8U );
CvMat* disp = cvCreateMat( imageSize.height,
imageSize.width, CV_16S );
CvMat* vdisp = cvCreateMat( imageSize.height,
imageSize.width, CV_8U );
CvMat* pair;
double R1[3][3], R2[3][3], P1[3][4], P2[3][4];
