#include "opencv2/core/core.hpp" #include "opencv2/imgproc/imgproc.hpp" #include "opencv2/calib3d/calib3d.hpp" #include "opencv2/highgui/highgui.hpp" #include #include #include using namespace cv; using namespace std; void help() { printf( "This is a camera calibration sample.\n" "Usage: calibration\n" " -w= # the number of inner corners per one of board dimension\n" " -h= # the number of inner corners per another board dimension\n" " [-pt]= # the type of pattern: chessboard or circles' grid\n" " [-n]= # the number of frames to use for calibration\n" " # (if not specified, it will be set to the number\n" " # of board views actually available)\n" " [-d]= # a minimum delay in ms between subsequent attempts to capture a next view\n" " # (used only for video capturing)\n" " [-s]= # square size in some user-defined units (1 by default)\n" " [-o]= # the output filename for intrinsic [and extrinsic] parameters\n" " [-op] # write detected feature points\n" " [-oe] # write extrinsic parameters\n" " [-zt] # assume zero tangential distortion\n" " [-a]= # fix aspect ratio (fx/fy)\n" " [-p] # fix the principal point at the center\n" " [-v] # flip the captured images around the horizontal axis\n" " [-V] # use a video file, and not an image list, uses\n" " # [input_data] string for the video file name\n" " [-su] # show undistorted images after calibration\n" " [-input_data]= # input data, one of the following:\n" " # - text file with a list of the images of the board\n" " # the text file can be generated with imagelist_creator\n" " # - name of video file with a video of the board\n" " [-cameraId]=# if input_data not specified, a live view from the camera is used\n" " \nExample command line for calibration from a live feed:\n" " ./calibration -w=4 -h=5 -s=0.025 -o=camera.yml -op -oe\n" " \n" " Example command line for calibration from a list of stored images:\n" " imagelist_creator image_list.xml *.png\n" " ./calibration -w=4 -h-5 -s=0.025 -o=camera.yml -op -oe -input_data=image_list.xml\n" " where image_list.xml is the standard OpenCV XML/YAML\n" " use imagelist_creator to create the xml or yaml list\n" " file consisting of the list of strings, e.g.:\n" " \n" "\n" "\n" "\n" "view000.png\n" "view001.png\n" "\n" "view003.png\n" "view010.png\n" "one_extra_view.jpg\n" "\n" "\n" "\nWhen the live video from camera is used as input, the following hot-keys may be used:\n" " , 'q' - quit the program\n" " 'g' - start capturing images\n" " 'u' - switch undistortion on/off\n"); } enum { DETECTION = 0, CAPTURING = 1, CALIBRATED = 2 }; enum Pattern { CHESSBOARD, CIRCLES_GRID, ASYMMETRIC_CIRCLES_GRID }; static double computeReprojectionErrors( const vector >& objectPoints, const vector >& imagePoints, const vector& rvecs, const vector& tvecs, const Mat& cameraMatrix, const Mat& distCoeffs, vector& perViewErrors ) { vector imagePoints2; int i, totalPoints = 0; double totalErr = 0, err; perViewErrors.resize(objectPoints.size()); for( i = 0; i < (int)objectPoints.size(); i++ ) { projectPoints(Mat(objectPoints[i]), rvecs[i], tvecs[i], cameraMatrix, distCoeffs, imagePoints2); err = norm(Mat(imagePoints[i]), Mat(imagePoints2), CV_L2); int n = (int)objectPoints[i].size(); perViewErrors[i] = (float)std::sqrt(err*err/n); totalErr += err*err; totalPoints += n; } return std::sqrt(totalErr/totalPoints); } static void calcChessboardCorners(Size boardSize, float squareSize, vector& corners, Pattern patternType = CHESSBOARD) { corners.resize(0); switch(patternType) { case CHESSBOARD: case CIRCLES_GRID: 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)); break; case ASYMMETRIC_CIRCLES_GRID: for( int i = 0; i < boardSize.height; i++ ) for( int j = 0; j < boardSize.width; j++ ) corners.push_back(Point3f(float((2*j + i % 2)*squareSize), float(i*squareSize), 0)); break; default: CV_Error(CV_StsBadArg, "Unknown pattern type\n"); } } static bool runCalibration( vector > imagePoints, Size imageSize, Size boardSize, Pattern patternType, float squareSize, float aspectRatio, int flags, Mat& cameraMatrix, Mat& distCoeffs, vector& rvecs, vector& tvecs, vector& reprojErrs, double& totalAvgErr) { cameraMatrix = Mat::eye(3, 3, CV_64F); if( flags & CV_CALIB_FIX_ASPECT_RATIO ) cameraMatrix.at(0,0) = aspectRatio; distCoeffs = Mat::zeros(8, 1, CV_64F); vector > objectPoints(1); calcChessboardCorners(boardSize, squareSize, objectPoints[0], patternType); objectPoints.resize(imagePoints.size(),objectPoints[0]); double rms = calibrateCamera(objectPoints, imagePoints, imageSize, cameraMatrix, distCoeffs, rvecs, tvecs, flags|CV_CALIB_FIX_K4|CV_CALIB_FIX_K5); ///*|CV_CALIB_FIX_K3*/|CV_CALIB_FIX_K4|CV_CALIB_FIX_K5); printf("RMS error reported by calibrateCamera: %g\n", rms); bool ok = checkRange(cameraMatrix) && checkRange(distCoeffs); totalAvgErr = computeReprojectionErrors(objectPoints, imagePoints, rvecs, tvecs, cameraMatrix, distCoeffs, reprojErrs); return ok; } void saveCameraParams( const string& filename, Size imageSize, Size boardSize, float squareSize, float aspectRatio, int flags, const Mat& cameraMatrix, const Mat& distCoeffs, const vector& rvecs, const vector& tvecs, const vector& reprojErrs, const vector >& imagePoints, double totalAvgErr ) { FileStorage fs( filename, FileStorage::WRITE ); time_t t; time( &t ); struct tm *t2 = localtime( &t ); char buf[1024]; strftime( buf, sizeof(buf)-1, "%c", t2 ); fs << "calibration_time" << buf; if( !rvecs.empty() || !reprojErrs.empty() ) fs << "nframes" << (int)std::max(rvecs.size(), reprojErrs.size()); fs << "image_width" << imageSize.width; fs << "image_height" << imageSize.height; fs << "board_width" << boardSize.width; fs << "board_height" << boardSize.height; fs << "square_size" << squareSize; if( flags & CV_CALIB_FIX_ASPECT_RATIO ) fs << "aspectRatio" << aspectRatio; if( flags != 0 ) { sprintf( buf, "flags: %s%s%s%s", flags & CV_CALIB_USE_INTRINSIC_GUESS ? "+use_intrinsic_guess" : "", flags & CV_CALIB_FIX_ASPECT_RATIO ? "+fix_aspectRatio" : "", flags & CV_CALIB_FIX_PRINCIPAL_POINT ? "+fix_principal_point" : "", flags & CV_CALIB_ZERO_TANGENT_DIST ? "+zero_tangent_dist" : "" ); cvWriteComment( *fs, buf, 0 ); } fs << "flags" << flags; fs << "camera_matrix" << cameraMatrix; fs << "distortion_coefficients" << distCoeffs; fs << "avg_reprojection_error" << totalAvgErr; if( !reprojErrs.empty() ) fs << "per_view_reprojection_errors" << Mat(reprojErrs); if( !rvecs.empty() && !tvecs.empty() ) { CV_Assert(rvecs[0].type() == tvecs[0].type()); Mat bigmat((int)rvecs.size(), 6, rvecs[0].type()); for( int i = 0; i < (int)rvecs.size(); i++ ) { Mat r = bigmat(Range(i, i+1), Range(0,3)); Mat t = bigmat(Range(i, i+1), Range(3,6)); CV_Assert(rvecs[i].rows == 3 && rvecs[i].cols == 1); CV_Assert(tvecs[i].rows == 3 && tvecs[i].cols == 1); //*.t() is MatExpr (not Mat) so we can use assignment operator r = rvecs[i].t(); t = tvecs[i].t(); } cvWriteComment( *fs, "a set of 6-tuples (rotation vector + translation vector) for each view", 0 ); fs << "extrinsic_parameters" << bigmat; } if( !imagePoints.empty() ) { Mat imagePtMat((int)imagePoints.size(), imagePoints[0].size(), CV_32FC2); for( int i = 0; i < (int)imagePoints.size(); i++ ) { Mat r = imagePtMat.row(i).reshape(2, imagePtMat.cols); Mat imgpti(imagePoints[i]); imgpti.copyTo(r); } fs << "image_points" << imagePtMat; } } static bool readStringList( const string& filename, vector& 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; } bool runAndSave(const string& outputFilename, const vector >& imagePoints, Size imageSize, Size boardSize, Pattern patternType, float squareSize, float aspectRatio, int flags, Mat& cameraMatrix, Mat& distCoeffs, bool writeExtrinsics, bool writePoints ) { vector rvecs, tvecs; vector reprojErrs; double totalAvgErr = 0; bool ok = runCalibration(imagePoints, imageSize, boardSize, patternType, squareSize, aspectRatio, flags, cameraMatrix, distCoeffs, rvecs, tvecs, reprojErrs, totalAvgErr); printf("%s. avg reprojection error = %.2f\n", ok ? "Calibration succeeded" : "Calibration failed", totalAvgErr); if( ok ) saveCameraParams( outputFilename, imageSize, boardSize, squareSize, aspectRatio, flags, cameraMatrix, distCoeffs, writeExtrinsics ? rvecs : vector(), writeExtrinsics ? tvecs : vector(), writeExtrinsics ? reprojErrs : vector(), writePoints ? imagePoints : vector >(), totalAvgErr ); return ok; } int main( int argc, const char** argv ) { help(); CommandLineParser parser(argc, argv); Size boardSize, imageSize; boardSize.width = parser.get("w"); boardSize.height = parser.get("h"); float squareSize = parser.get("s", 1.f); float aspectRatio = parser.get("a", 1.f); Mat cameraMatrix, distCoeffs; string outputFilename = parser.get("o","out_camera_data.yml"); string inputFilename = parser.get("input_data"); int nframes = parser.get("n", 10); bool writeExtrinsics = parser.get("oe"); bool writePoints = parser.get("op"); bool flipVertical = parser.get("v"); bool showUndistorted = parser.get("su"); bool videofile = parser.get("V"); unsigned int delay = parser.get("d", 1000); unsigned int cameraId = parser.get("cameraId",0); bool undistortImage = false; int flags = 0; VideoCapture capture; clock_t prevTimestamp = 0; int mode = DETECTION; vector > imagePoints; vector imageList; Pattern pattern = CHESSBOARD; if( (boardSize.width < 1) || (boardSize.height < 1)) { help(); return fprintf( stderr, "Invalid board width or height. It must be more than zero\n" ), -1; } if(parser.get("pt")=="circles") pattern = CIRCLES_GRID; else if(parser.get("pt")=="acircles") pattern = ASYMMETRIC_CIRCLES_GRID; if(squareSize <= 0) { help(); return fprintf( stderr, "Invalid board square width. It must be more than zero.\n" ), -1; } if(nframes < 4) { help(); return printf("Invalid number of images. It must be more than 3\n" ), -1; } if(aspectRatio <= 0) { help(); return printf("Invalid aspect ratio. It must be more than zero\n" ), -1; } else flags |= CV_CALIB_FIX_ASPECT_RATIO; if(!delay) { help(); return printf("Invalid delay. It must be more than zero.\n" ), -1; } if(parser.get("zt")) flags |= CV_CALIB_ZERO_TANGENT_DIST; if(parser.get("p")) flags |= CV_CALIB_FIX_PRINCIPAL_POINT; if( !inputFilename.empty() ) { if( !videofile && readStringList(inputFilename, imageList) ) mode = CAPTURING; else capture.open(inputFilename); } else capture.open(cameraId); if( !capture.isOpened() && imageList.empty() ) return fprintf( stderr, "Could not initialize video (%d) capture\n",cameraId ), -2; if( !imageList.empty() ) nframes = (int)imageList.size(); namedWindow( "Image View", 1 ); int i; for(i = 0;;i++) { Mat view, viewGray; bool blink = false; if( capture.isOpened() ) { Mat view0; capture >> view0; view0.copyTo(view); } else if( i < (int)imageList.size() ) view = imread(imageList[i], 1); if(!view.data) { if( imagePoints.size() > 0 ) runAndSave(outputFilename, imagePoints, imageSize, boardSize, pattern, squareSize, aspectRatio, flags, cameraMatrix, distCoeffs, writeExtrinsics, writePoints); break; } imageSize = view.size(); if( flipVertical ) flip( view, view, 0 ); vector pointbuf; cvtColor(view, viewGray, CV_BGR2GRAY); bool found; switch( pattern ) { case CHESSBOARD: found = findChessboardCorners( view, boardSize, pointbuf, CV_CALIB_CB_ADAPTIVE_THRESH | CV_CALIB_CB_FAST_CHECK | CV_CALIB_CB_NORMALIZE_IMAGE); break; case CIRCLES_GRID: found = findCirclesGrid( view, boardSize, pointbuf ); break; case ASYMMETRIC_CIRCLES_GRID: found = findCirclesGrid( view, boardSize, pointbuf, CALIB_CB_ASYMMETRIC_GRID ); break; default: return fprintf( stderr, "Unknown pattern type\n" ), -1; } // improve the found corners' coordinate accuracy if( pattern == CHESSBOARD && found) cornerSubPix( viewGray, pointbuf, Size(11,11), Size(-1,-1), TermCriteria( CV_TERMCRIT_EPS+CV_TERMCRIT_ITER, 30, 0.1 )); if( mode == CAPTURING && found && (!capture.isOpened() || clock() - prevTimestamp > delay*1e-3*CLOCKS_PER_SEC) ) { imagePoints.push_back(pointbuf); prevTimestamp = clock(); blink = capture.isOpened(); } if(found) drawChessboardCorners( view, boardSize, Mat(pointbuf), found ); string msg = mode == CAPTURING ? "100/100" : mode == CALIBRATED ? "Calibrated" : "Press 'g' to start"; int baseLine = 0; Size textSize = getTextSize(msg, 1, 1, 1, &baseLine); Point textOrigin(view.cols - 2*textSize.width - 10, view.rows - 2*baseLine - 10); if( mode == CAPTURING ) { if(undistortImage) msg = format( "%d/%d Undist", (int)imagePoints.size(), nframes ); else msg = format( "%d/%d", (int)imagePoints.size(), nframes ); } putText( view, msg, textOrigin, 1, 1, mode != CALIBRATED ? Scalar(0,0,255) : Scalar(0,255,0)); if( blink ) bitwise_not(view, view); if( mode == CALIBRATED && undistortImage ) { Mat temp = view.clone(); undistort(temp, view, cameraMatrix, distCoeffs); } imshow("Image View", view); int key = 0xff & waitKey(capture.isOpened() ? 50 : 500); if( (key & 255) == 27 ) break; if( key == 'u' && mode == CALIBRATED ) undistortImage = !undistortImage; if( capture.isOpened() && key == 'g' ) { mode = CAPTURING; imagePoints.clear(); } if( mode == CAPTURING && imagePoints.size() >= (unsigned)nframes ) { if( runAndSave(outputFilename, imagePoints, imageSize, boardSize, pattern, squareSize, aspectRatio, flags, cameraMatrix, distCoeffs, writeExtrinsics, writePoints)) mode = CALIBRATED; else mode = DETECTION; if( !capture.isOpened() ) break; } } if( !capture.isOpened() && showUndistorted ) { Mat view, rview, map1, map2; initUndistortRectifyMap(cameraMatrix, distCoeffs, Mat(), getOptimalNewCameraMatrix(cameraMatrix, distCoeffs, imageSize, 1, imageSize, 0), imageSize, CV_16SC2, map1, map2); for( i = 0; i < (int)imageList.size(); i++ ) { view = imread(imageList[i], 1); if(!view.data) continue; //undistort( view, rview, cameraMatrix, distCoeffs, cameraMatrix ); remap(view, rview, map1, map2, INTER_LINEAR); imshow("Image View", rview); int c = 0xff & waitKey(); if( (c & 255) == 27 || c == 'q' || c == 'Q' ) break; } } return 0; }