#include #include #include #include #include #include #include "aruco_samples_utility.hpp" using namespace std; using namespace cv; namespace { const char* about = "Calibration using a ChArUco board\n" " To capture a frame for calibration, press 'c',\n" " If input comes from video, press any key for next frame\n" " To finish capturing, press 'ESC' key and calibration starts.\n"; const char* keys = "{w | | Number of squares in X direction }" "{h | | Number of squares in Y direction }" "{sl | | Square side length (in meters) }" "{ml | | Marker side length (in meters) }" "{d | | dictionary: DICT_4X4_50=0, DICT_4X4_100=1, DICT_4X4_250=2," "DICT_4X4_1000=3, DICT_5X5_50=4, DICT_5X5_100=5, DICT_5X5_250=6, DICT_5X5_1000=7, " "DICT_6X6_50=8, DICT_6X6_100=9, DICT_6X6_250=10, DICT_6X6_1000=11, DICT_7X7_50=12," "DICT_7X7_100=13, DICT_7X7_250=14, DICT_7X7_1000=15, DICT_ARUCO_ORIGINAL=16," "DICT_APRILTAG_16h5=17, DICT_APRILTAG_25h9=18, DICT_APRILTAG_36h10=19, DICT_APRILTAG_36h11=20, DICT_ARUCO_MIP_36h12=21}" "{cd | | Input file with custom dictionary }" "{@outfile |cam.yml| Output file with calibrated camera parameters }" "{v | | Input from video file, if ommited, input comes from camera }" "{ci | 0 | Camera id if input doesnt come from video (-v) }" "{dp | | File of marker detector parameters }" "{rs | false | Apply refind strategy }" "{zt | false | Assume zero tangential distortion }" "{a | | Fix aspect ratio (fx/fy) to this value }" "{pc | false | Fix the principal point at the center }" "{sc | false | Show detected chessboard corners after calibration }"; } int main(int argc, char *argv[]) { CommandLineParser parser(argc, argv, keys); parser.about(about); if(argc < 7) { parser.printMessage(); return 0; } int squaresX = parser.get("w"); int squaresY = parser.get("h"); float squareLength = parser.get("sl"); float markerLength = parser.get("ml"); string outputFile = parser.get(0); bool showChessboardCorners = parser.get("sc"); int calibrationFlags = 0; float aspectRatio = 1; if(parser.has("a")) { calibrationFlags |= CALIB_FIX_ASPECT_RATIO; aspectRatio = parser.get("a"); } if(parser.get("zt")) calibrationFlags |= CALIB_ZERO_TANGENT_DIST; if(parser.get("pc")) calibrationFlags |= CALIB_FIX_PRINCIPAL_POINT; aruco::DetectorParameters detectorParams = readDetectorParamsFromCommandLine(parser); aruco::Dictionary dictionary = readDictionatyFromCommandLine(parser); bool refindStrategy = parser.get("rs"); int camId = parser.get("ci"); String video; if(parser.has("v")) { video = parser.get("v"); } if(!parser.check()) { parser.printErrors(); return 0; } VideoCapture inputVideo; int waitTime; if(!video.empty()) { inputVideo.open(video); waitTime = 0; } else { inputVideo.open(camId); waitTime = 10; } aruco::CharucoParameters charucoParams; if(refindStrategy) { charucoParams.tryRefineMarkers = true; } //! [CalibrationWithCharucoBoard1] // Create charuco board object and CharucoDetector aruco::CharucoBoard board(Size(squaresX, squaresY), squareLength, markerLength, dictionary); aruco::CharucoDetector detector(board, charucoParams, detectorParams); // Collect data from each frame vector allCharucoCorners, allCharucoIds; vector> allImagePoints; vector> allObjectPoints; vector allImages; Size imageSize; while(inputVideo.grab()) { Mat image, imageCopy; inputVideo.retrieve(image); vector markerIds; vector> markerCorners; Mat currentCharucoCorners, currentCharucoIds; vector currentObjectPoints; vector currentImagePoints; // Detect ChArUco board detector.detectBoard(image, currentCharucoCorners, currentCharucoIds); //! [CalibrationWithCharucoBoard1] // Draw results image.copyTo(imageCopy); if(!markerIds.empty()) { aruco::drawDetectedMarkers(imageCopy, markerCorners); } if(currentCharucoCorners.total() > 3) { aruco::drawDetectedCornersCharuco(imageCopy, currentCharucoCorners, currentCharucoIds); } putText(imageCopy, "Press 'c' to add current frame. 'ESC' to finish and calibrate", Point(10, 20), FONT_HERSHEY_SIMPLEX, 0.5, Scalar(255, 0, 0), 2); imshow("out", imageCopy); // Wait for key pressed char key = (char)waitKey(waitTime); if(key == 27) { break; } //! [CalibrationWithCharucoBoard2] if(key == 'c' && currentCharucoCorners.total() > 3) { // Match image points board.matchImagePoints(currentCharucoCorners, currentCharucoIds, currentObjectPoints, currentImagePoints); if(currentImagePoints.empty() || currentObjectPoints.empty()) { cout << "Point matching failed, try again." << endl; continue; } cout << "Frame captured" << endl; allCharucoCorners.push_back(currentCharucoCorners); allCharucoIds.push_back(currentCharucoIds); allImagePoints.push_back(currentImagePoints); allObjectPoints.push_back(currentObjectPoints); allImages.push_back(image); imageSize = image.size(); } } //! [CalibrationWithCharucoBoard2] if(allCharucoCorners.size() < 4) { cerr << "Not enough corners for calibration" << endl; return 0; } //! [CalibrationWithCharucoBoard3] Mat cameraMatrix, distCoeffs; if(calibrationFlags & CALIB_FIX_ASPECT_RATIO) { cameraMatrix = Mat::eye(3, 3, CV_64F); cameraMatrix.at(0, 0) = aspectRatio; } // Calibrate camera using ChArUco double repError = calibrateCamera(allObjectPoints, allImagePoints, imageSize, cameraMatrix, distCoeffs, noArray(), noArray(), noArray(), noArray(), noArray(), calibrationFlags); //! [CalibrationWithCharucoBoard3] bool saveOk = saveCameraParams(outputFile, imageSize, aspectRatio, calibrationFlags, cameraMatrix, distCoeffs, repError); if(!saveOk) { cerr << "Cannot save output file" << endl; return 0; } cout << "Rep Error: " << repError << endl; cout << "Calibration saved to " << outputFile << endl; // Show interpolated charuco corners for debugging if(showChessboardCorners) { for(size_t frame = 0; frame < allImages.size(); frame++) { Mat imageCopy = allImages[frame].clone(); if(allCharucoCorners[frame].total() > 0) { aruco::drawDetectedCornersCharuco(imageCopy, allCharucoCorners[frame], allCharucoIds[frame]); } imshow("out", imageCopy); char key = (char)waitKey(0); if(key == 27) { break; } } } return 0; }