This source file includes following definitions.
- help
- calcChessboardCorners
- run3Calibration
- readStringList
- main
#include "opencv2/calib3d/calib3d.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/imgcodecs/imgcodecs.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <stdio.h>
#include <string.h>
#include <time.h>
using namespace cv;
using namespace std;
enum { DETECTION = 0, CAPTURING = 1, CALIBRATED = 2 };
static void help()
{
printf( "\nThis is a camera calibration sample that calibrates 3 horizontally placed cameras together.\n"
"Usage: 3calibration\n"
" -w <board_width> # the number of inner corners per one of board dimension\n"
" -h <board_height> # the number of inner corners per another board dimension\n"
" [-s <squareSize>] # square size in some user-defined units (1 by default)\n"
" [-o <out_camera_params>] # the output filename for intrinsic [and extrinsic] parameters\n"
" [-zt] # assume zero tangential distortion\n"
" [-a <aspectRatio>] # fix aspect ratio (fx/fy)\n"
" [-p] # fix the principal point at the center\n"
" [input_data] # input data - text file with a list of the images of the board\n"
"\n" );
}
static void calcChessboardCorners(Size boardSize, float squareSize, vector<Point3f>& corners)
{
corners.resize(0);
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 run3Calibration( vector<vector<Point2f> > imagePoints1,
vector<vector<Point2f> > imagePoints2,
vector<vector<Point2f> > imagePoints3,
Size imageSize, Size boardSize,
float squareSize, float aspectRatio,
int flags,
Mat& cameraMatrix1, Mat& distCoeffs1,
Mat& cameraMatrix2, Mat& distCoeffs2,
Mat& cameraMatrix3, Mat& distCoeffs3,
Mat& R12, Mat& T12, Mat& R13, Mat& T13)
{
int c, i;
vector<vector<Point3f> > objpt(1);
vector<vector<Point2f> > imgpt;
calcChessboardCorners(boardSize, squareSize, objpt[0]);
vector<Mat> rvecs, tvecs;
for( c = 1; c <= 3; c++ )
{
const vector<vector<Point2f> >& imgpt0 = c == 1 ? imagePoints1 : c == 2 ? imagePoints2 : imagePoints3;
imgpt.clear();
int N = 0;
for( i = 0; i < (int)imgpt0.size(); i++ )
if( !imgpt0[i].empty() )
{
imgpt.push_back(imgpt0[i]);
N += (int)imgpt0[i].size();
}
if( imgpt.size() < 3 )
{
printf("Error: not enough views for camera %d\n", c);
return false;
}
objpt.resize(imgpt.size(),objpt[0]);
Mat cameraMatrix = Mat::eye(3, 3, CV_64F);
if( flags & CALIB_FIX_ASPECT_RATIO )
cameraMatrix.at<double>(0,0) = aspectRatio;
Mat distCoeffs = Mat::zeros(5, 1, CV_64F);
double err = calibrateCamera(objpt, imgpt, imageSize, cameraMatrix,
distCoeffs, rvecs, tvecs,
flags|CALIB_FIX_K3);
bool ok = checkRange(cameraMatrix) && checkRange(distCoeffs);
if(!ok)
{
printf("Error: camera %d was not calibrated\n", c);
return false;
}
printf("Camera %d calibration reprojection error = %g\n", c, sqrt(err/N));
if( c == 1 )
cameraMatrix1 = cameraMatrix, distCoeffs1 = distCoeffs;
else if( c == 2 )
cameraMatrix2 = cameraMatrix, distCoeffs2 = distCoeffs;
else
cameraMatrix3 = cameraMatrix, distCoeffs3 = distCoeffs;
}
vector<vector<Point2f> > imgpt_right;
for( c = 2; c <= 3; c++ )
{
const vector<vector<Point2f> >& imgpt0 = c == 2 ? imagePoints2 : imagePoints3;
imgpt.clear();
imgpt_right.clear();
int N = 0;
for( i = 0; i < (int)std::min(imagePoints1.size(), imgpt0.size()); i++ )
if( !imagePoints1.empty() && !imgpt0[i].empty() )
{
imgpt.push_back(imagePoints1[i]);
imgpt_right.push_back(imgpt0[i]);
N += (int)imgpt0[i].size();
}
if( imgpt.size() < 3 )
{
printf("Error: not enough shared views for cameras 1 and %d\n", c);
return false;
}
objpt.resize(imgpt.size(),objpt[0]);
Mat cameraMatrix = c == 2 ? cameraMatrix2 : cameraMatrix3;
Mat distCoeffs = c == 2 ? distCoeffs2 : distCoeffs3;
Mat R, T, E, F;
double err = stereoCalibrate(objpt, imgpt, imgpt_right, cameraMatrix1, distCoeffs1,
cameraMatrix, distCoeffs,
imageSize, R, T, E, F,
CALIB_FIX_INTRINSIC,
TermCriteria(TermCriteria::COUNT, 30, 0));
printf("Pair (1,%d) calibration reprojection error = %g\n", c, sqrt(err/(N*2)));
if( c == 2 )
{
cameraMatrix2 = cameraMatrix;
distCoeffs2 = distCoeffs;
R12 = R; T12 = T;
}
else
{
R13 = R; T13 = T;
}
}
return true;
}
static bool readStringList( const string& filename, vector<string>& l )
{
l.resize(0);
FileStorage fs(filename, FileStorage::READ);
if( !fs.isOpened() )
return false;
FileNode n = fs.getFirstTopLevelNode();
if( n.type() != FileNode::SEQ )
return false;
FileNodeIterator it = n.begin(), it_end = n.end();
for( ; it != it_end; ++it )
l.push_back((string)*it);
return true;
}
int main( int argc, char** argv )
{
int i, k;
int flags = 0;
Size boardSize, imageSize;
float squareSize = 1.f, aspectRatio = 1.f;
const char* outputFilename = "out_camera_data.yml";
const char* inputFilename = 0;
vector<vector<Point2f> > imgpt[3];
vector<string> imageList;
if(argc < 2)
{
help();
return 1;
}
for( i = 1; i < argc; i++ )
{
const char* s = argv[i];
if( strcmp( s, "-w" ) == 0 )
{
if( sscanf( argv[++i], "%u", &boardSize.width ) != 1 || boardSize.width <= 0 )
return fprintf( stderr, "Invalid board width\n" ), -1;
}
else if( strcmp( s, "-h" ) == 0 )
{
if( sscanf( argv[++i], "%u", &boardSize.height ) != 1 || boardSize.height <= 0 )
return fprintf( stderr, "Invalid board height\n" ), -1;
}
else if( strcmp( s, "-s" ) == 0 )
{
if( sscanf( argv[++i], "%f", &squareSize ) != 1 || squareSize <= 0 )
return fprintf( stderr, "Invalid board square width\n" ), -1;
}
else if( strcmp( s, "-a" ) == 0 )
{
if( sscanf( argv[++i], "%f", &aspectRatio ) != 1 || aspectRatio <= 0 )
return printf("Invalid aspect ratio\n" ), -1;
flags |= CALIB_FIX_ASPECT_RATIO;
}
else if( strcmp( s, "-zt" ) == 0 )
{
flags |= CALIB_ZERO_TANGENT_DIST;
}
else if( strcmp( s, "-p" ) == 0 )
{
flags |= CALIB_FIX_PRINCIPAL_POINT;
}
else if( strcmp( s, "-o" ) == 0 )
{
outputFilename = argv[++i];
}
else if( s[0] != '-' )
{
inputFilename = s;
}
else
return fprintf( stderr, "Unknown option %s", s ), -1;
}
if( !inputFilename ||
!readStringList(inputFilename, imageList) ||
imageList.size() == 0 || imageList.size() % 3 != 0 )
{
printf("Error: the input image list is not specified, or can not be read, or the number of files is not divisible by 3\n");
return -1;
}
Mat view, viewGray;
Mat cameraMatrix[3], distCoeffs[3], R[3], P[3], R12, T12;
for( k = 0; k < 3; k++ )
{
cameraMatrix[k] = Mat_<double>::eye(3,3);
cameraMatrix[k].at<double>(0,0) = aspectRatio;
cameraMatrix[k].at<double>(1,1) = 1;
distCoeffs[k] = Mat_<double>::zeros(5,1);
}
Mat R13=Mat_<double>::eye(3,3), T13=Mat_<double>::zeros(3,1);
FileStorage fs;
namedWindow( "Image View", 0 );
for( k = 0; k < 3; k++ )
imgpt[k].resize(imageList.size()/3);
for( i = 0; i < (int)(imageList.size()/3); i++ )
{
for( k = 0; k < 3; k++ )
{
int k1 = k == 0 ? 2 : k == 1 ? 0 : 1;
printf("%s\n", imageList[i*3+k].c_str());
view = imread(imageList[i*3+k], 1);
if(!view.empty())
{
vector<Point2f> ptvec;
imageSize = view.size();
cvtColor(view, viewGray, COLOR_BGR2GRAY);
bool found = findChessboardCorners( view, boardSize, ptvec, CALIB_CB_ADAPTIVE_THRESH );
drawChessboardCorners( view, boardSize, Mat(ptvec), found );
if( found )
{
imgpt[k1][i].resize(ptvec.size());
std::copy(ptvec.begin(), ptvec.end(), imgpt[k1][i].begin());
}
}
}
}
printf("Running calibration ...\n");
run3Calibration(imgpt[0], imgpt[1], imgpt[2], imageSize,
boardSize, squareSize, aspectRatio, flags|CALIB_FIX_K4|CALIB_FIX_K5,
cameraMatrix[0], distCoeffs[0],
cameraMatrix[1], distCoeffs[1],
cameraMatrix[2], distCoeffs[2],
R12, T12, R13, T13);
fs.open(outputFilename, FileStorage::WRITE);
fs << "cameraMatrix1" << cameraMatrix[0];
fs << "cameraMatrix2" << cameraMatrix[1];
fs << "cameraMatrix3" << cameraMatrix[2];
fs << "distCoeffs1" << distCoeffs[0];
fs << "distCoeffs2" << distCoeffs[1];
fs << "distCoeffs3" << distCoeffs[2];
fs << "R12" << R12;
fs << "T12" << T12;
fs << "R13" << R13;
fs << "T13" << T13;
fs << "imageWidth" << imageSize.width;
fs << "imageHeight" << imageSize.height;
Mat Q;
double ratio = rectify3Collinear(cameraMatrix[0], distCoeffs[0], cameraMatrix[1],
distCoeffs[1], cameraMatrix[2], distCoeffs[2],
imgpt[0], imgpt[2],
imageSize, R12, T12, R13, T13,
R[0], R[1], R[2], P[0], P[1], P[2], Q, -1.,
imageSize, 0, 0, CALIB_ZERO_DISPARITY);
Mat map1[3], map2[3];
fs << "R1" << R[0];
fs << "R2" << R[1];
fs << "R3" << R[2];
fs << "P1" << P[0];
fs << "P2" << P[1];
fs << "P3" << P[2];
fs << "disparityRatio" << ratio;
fs.release();
printf("Disparity ratio = %g\n", ratio);
for( k = 0; k < 3; k++ )
initUndistortRectifyMap(cameraMatrix[k], distCoeffs[k], R[k], P[k], imageSize, CV_16SC2, map1[k], map2[k]);
Mat canvas(imageSize.height, imageSize.width*3, CV_8UC3), small_canvas;
destroyWindow("view");
canvas = Scalar::all(0);
for( i = 0; i < (int)(imageList.size()/3); i++ )
{
canvas = Scalar::all(0);
for( k = 0; k < 3; k++ )
{
int k1 = k == 0 ? 2 : k == 1 ? 0 : 1;
int k2 = k == 0 ? 1 : k == 1 ? 0 : 2;
view = imread(imageList[i*3+k], 1);
if(view.empty())
continue;
Mat rview = canvas.colRange(k2*imageSize.width, (k2+1)*imageSize.width);
remap(view, rview, map1[k1], map2[k1], INTER_LINEAR);
}
printf("%s %s %s\n", imageList[i*3].c_str(), imageList[i*3+1].c_str(), imageList[i*3+2].c_str());
resize( canvas, small_canvas, Size(1500, 1500/3) );
for( k = 0; k < small_canvas.rows; k += 16 )
line(small_canvas, Point(0, k), Point(small_canvas.cols, k), Scalar(0,255,0), 1);
imshow("rectified", small_canvas);
int c = waitKey(0);
if( c == 27 || c == 'q' || c == 'Q' )
break;
}
return 0;
}