opencv_contrib/modules/aruco/test/test_charucodetection.cpp

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#include "test_precomp.hpp"

namespace opencv_test { namespace {

static double deg2rad(double deg) { return deg * CV_PI / 180.; }

/**
 * @brief Get rvec and tvec from yaw, pitch and distance
 */
static void getSyntheticRT(double yaw, double pitch, double distance, Mat &rvec, Mat &tvec) {

    rvec = Mat(3, 1, CV_64FC1);
    tvec = Mat(3, 1, CV_64FC1);

    // Rvec
    // first put the Z axis aiming to -X (like the camera axis system)
    Mat rotZ(3, 1, CV_64FC1);
    rotZ.ptr< double >(0)[0] = 0;
    rotZ.ptr< double >(0)[1] = 0;
    rotZ.ptr< double >(0)[2] = -0.5 * CV_PI;

    Mat rotX(3, 1, CV_64FC1);
    rotX.ptr< double >(0)[0] = 0.5 * CV_PI;
    rotX.ptr< double >(0)[1] = 0;
    rotX.ptr< double >(0)[2] = 0;

    Mat camRvec, camTvec;
    composeRT(rotZ, Mat(3, 1, CV_64FC1, Scalar::all(0)), rotX, Mat(3, 1, CV_64FC1, Scalar::all(0)),
              camRvec, camTvec);

    // now pitch and yaw angles
    Mat rotPitch(3, 1, CV_64FC1);
    rotPitch.ptr< double >(0)[0] = 0;
    rotPitch.ptr< double >(0)[1] = pitch;
    rotPitch.ptr< double >(0)[2] = 0;

    Mat rotYaw(3, 1, CV_64FC1);
    rotYaw.ptr< double >(0)[0] = yaw;
    rotYaw.ptr< double >(0)[1] = 0;
    rotYaw.ptr< double >(0)[2] = 0;

    composeRT(rotPitch, Mat(3, 1, CV_64FC1, Scalar::all(0)), rotYaw,
              Mat(3, 1, CV_64FC1, Scalar::all(0)), rvec, tvec);

    // compose both rotations
    composeRT(camRvec, Mat(3, 1, CV_64FC1, Scalar::all(0)), rvec,
              Mat(3, 1, CV_64FC1, Scalar::all(0)), rvec, tvec);

    // Tvec, just move in z (camera) direction the specific distance
    tvec.ptr< double >(0)[0] = 0.;
    tvec.ptr< double >(0)[1] = 0.;
    tvec.ptr< double >(0)[2] = distance;
}

/**
 * @brief Project a synthetic marker
 */
static void projectMarker(Mat &img, Ptr<aruco::Dictionary> dictionary, int id,
                          vector< Point3f > markerObjPoints, Mat cameraMatrix, Mat rvec, Mat tvec,
                          int markerBorder) {


    Mat markerImg;
    const int markerSizePixels = 100;
    aruco::drawMarker(dictionary, id, markerSizePixels, markerImg, markerBorder);

    Mat distCoeffs(5, 1, CV_64FC1, Scalar::all(0));
    vector< Point2f > corners;
    projectPoints(markerObjPoints, rvec, tvec, cameraMatrix, distCoeffs, corners);

    vector< Point2f > originalCorners;
    originalCorners.push_back(Point2f(0, 0));
    originalCorners.push_back(Point2f((float)markerSizePixels, 0));
    originalCorners.push_back(Point2f((float)markerSizePixels, (float)markerSizePixels));
    originalCorners.push_back(Point2f(0, (float)markerSizePixels));

    Mat transformation = getPerspectiveTransform(originalCorners, corners);

    Mat aux;
    const char borderValue = 127;
    warpPerspective(markerImg, aux, transformation, img.size(), INTER_NEAREST, BORDER_CONSTANT,
                    Scalar::all(borderValue));

    // copy only not-border pixels
    for(int y = 0; y < aux.rows; y++) {
        for(int x = 0; x < aux.cols; x++) {
            if(aux.at< unsigned char >(y, x) == borderValue) continue;
            img.at< unsigned char >(y, x) = aux.at< unsigned char >(y, x);
        }
    }
}

/**
 * @brief Get a synthetic image of Chessboard in perspective
 */
static Mat projectChessboard(int squaresX, int squaresY, float squareSize, Size imageSize,
                             Mat cameraMatrix, Mat rvec, Mat tvec) {

    Mat img(imageSize, CV_8UC1, Scalar::all(255));
    Mat distCoeffs(5, 1, CV_64FC1, Scalar::all(0));

    for(int y = 0; y < squaresY; y++) {
        float startY = float(y) * squareSize;
        for(int x = 0; x < squaresX; x++) {
            if(y % 2 != x % 2) continue;
            float startX = float(x) * squareSize;

            vector< Point3f > squareCorners;
            squareCorners.push_back(Point3f(startX, startY, 0));
            squareCorners.push_back(squareCorners[0] + Point3f(squareSize, 0, 0));
            squareCorners.push_back(squareCorners[0] + Point3f(squareSize, squareSize, 0));
            squareCorners.push_back(squareCorners[0] + Point3f(0, squareSize, 0));

            vector< vector< Point2f > > projectedCorners;
            projectedCorners.push_back(vector< Point2f >());
            projectPoints(squareCorners, rvec, tvec, cameraMatrix, distCoeffs, projectedCorners[0]);

            vector< vector< Point > > projectedCornersInt;
            projectedCornersInt.push_back(vector< Point >());

            for(int k = 0; k < 4; k++)
                projectedCornersInt[0]
                    .push_back(Point((int)projectedCorners[0][k].x, (int)projectedCorners[0][k].y));

            fillPoly(img, projectedCornersInt, Scalar::all(0));
        }
    }

    return img;
}


/**
 * @brief Check pose estimation of charuco board
 */
static Mat projectCharucoBoard(Ptr<aruco::CharucoBoard> &board, Mat cameraMatrix, double yaw,
                               double pitch, double distance, Size imageSize, int markerBorder,
                               Mat &rvec, Mat &tvec) {

    getSyntheticRT(yaw, pitch, distance, rvec, tvec);

    // project markers
    Mat img = Mat(imageSize, CV_8UC1, Scalar::all(255));
    for(unsigned int m = 0; m < board->ids.size(); m++) {
        projectMarker(img, board->dictionary, board->ids[m], board->objPoints[m], cameraMatrix, rvec,
                      tvec, markerBorder);
    }

    // project chessboard
    Mat chessboard =
        projectChessboard(board->getChessboardSize().width, board->getChessboardSize().height,
                          board->getSquareLength(), imageSize, cameraMatrix, rvec, tvec);

    for(unsigned int i = 0; i < chessboard.total(); i++) {
        if(chessboard.ptr< unsigned char >()[i] == 0) {
            img.ptr< unsigned char >()[i] = 0;
        }
    }

    return img;
}




/**
 * @brief Check Charuco detection
 */
class CV_CharucoDetection : public cvtest::BaseTest {
    public:
    CV_CharucoDetection();

    protected:
    void run(int);
};


CV_CharucoDetection::CV_CharucoDetection() {}


void CV_CharucoDetection::run(int) {

    int iter = 0;
    Mat cameraMatrix = Mat::eye(3, 3, CV_64FC1);
    Size imgSize(500, 500);
    Ptr<aruco::Dictionary> dictionary = aruco::getPredefinedDictionary(aruco::DICT_6X6_250);
    Ptr<aruco::CharucoBoard> board = aruco::CharucoBoard::create(4, 4, 0.03f, 0.015f, dictionary);

    cameraMatrix.at< double >(0, 0) = cameraMatrix.at< double >(1, 1) = 650;
    cameraMatrix.at< double >(0, 2) = imgSize.width / 2;
    cameraMatrix.at< double >(1, 2) = imgSize.height / 2;

    Mat distCoeffs(5, 1, CV_64FC1, Scalar::all(0));

    // for different perspectives
    for(double distance = 0.2; distance <= 0.4; distance += 0.2) {
        for(int yaw = 0; yaw < 360; yaw += 100) {
            for(int pitch = 30; pitch <= 90; pitch += 50) {

                int markerBorder = iter % 2 + 1;
                iter++;

                // create synthetic image
                Mat rvec, tvec;
                Mat img = projectCharucoBoard(board, cameraMatrix, deg2rad(pitch), deg2rad(yaw),
                                              distance, imgSize, markerBorder, rvec, tvec);

                // detect markers
                vector< vector< Point2f > > corners;
                vector< int > ids;
                Ptr<aruco::DetectorParameters> params = aruco::DetectorParameters::create();
                params->minDistanceToBorder = 3;
                params->markerBorderBits = markerBorder;
                aruco::detectMarkers(img, dictionary, corners, ids, params);

                if(ids.size() == 0) {
                    ts->printf(cvtest::TS::LOG, "Marker detection failed");
                    ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                    return;
                }

                // interpolate charuco corners
                vector< Point2f > charucoCorners;
                vector< int > charucoIds;

                if(iter % 2 == 0) {
                    aruco::interpolateCornersCharuco(corners, ids, img, board, charucoCorners,
                                                     charucoIds);
                } else {
                    aruco::interpolateCornersCharuco(corners, ids, img, board, charucoCorners,
                                                     charucoIds, cameraMatrix, distCoeffs);
                }

                // check results
                vector< Point2f > projectedCharucoCorners;
                projectPoints(board->chessboardCorners, rvec, tvec, cameraMatrix, distCoeffs,
                              projectedCharucoCorners);

                for(unsigned int i = 0; i < charucoIds.size(); i++) {

                    int currentId = charucoIds[i];

                    if(currentId >= (int)board->chessboardCorners.size()) {
                        ts->printf(cvtest::TS::LOG, "Invalid Charuco corner id");
                        ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                        return;
                    }

                    double repError = cv::norm(charucoCorners[i] - projectedCharucoCorners[currentId]);  // TODO cvtest


                    if(repError > 5.) {
                        ts->printf(cvtest::TS::LOG, "Charuco corner reprojection error too high");
                        ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                        return;
                    }
                }
            }
        }
    }
}



/**
 * @brief Check charuco pose estimation
 */
class CV_CharucoPoseEstimation : public cvtest::BaseTest {
    public:
    CV_CharucoPoseEstimation();

    protected:
    void run(int);
};


CV_CharucoPoseEstimation::CV_CharucoPoseEstimation() {}


void CV_CharucoPoseEstimation::run(int) {

    int iter = 0;
    Mat cameraMatrix = Mat::eye(3, 3, CV_64FC1);
    Size imgSize(500, 500);
    Ptr<aruco::Dictionary> dictionary = aruco::getPredefinedDictionary(aruco::DICT_6X6_250);
    Ptr<aruco::CharucoBoard> board = aruco::CharucoBoard::create(4, 4, 0.03f, 0.015f, dictionary);

    cameraMatrix.at< double >(0, 0) = cameraMatrix.at< double >(1, 1) = 650;
    cameraMatrix.at< double >(0, 2) = imgSize.width / 2;
    cameraMatrix.at< double >(1, 2) = imgSize.height / 2;

    Mat distCoeffs(5, 1, CV_64FC1, Scalar::all(0));
    // for different perspectives
    for(double distance = 0.2; distance <= 0.4; distance += 0.2) {
        for(int yaw = 0; yaw < 360; yaw += 100) {
            for(int pitch = 30; pitch <= 90; pitch += 50) {

                int markerBorder = iter % 2 + 1;
                iter++;

                // get synthetic image
                Mat rvec, tvec;
                Mat img = projectCharucoBoard(board, cameraMatrix, deg2rad(pitch), deg2rad(yaw),
                                              distance, imgSize, markerBorder, rvec, tvec);

                // detect markers
                vector< vector< Point2f > > corners;
                vector< int > ids;
                Ptr<aruco::DetectorParameters> params = aruco::DetectorParameters::create();
                params->minDistanceToBorder = 3;
                params->markerBorderBits = markerBorder;
                aruco::detectMarkers(img, dictionary, corners, ids, params);

                if(ids.size() == 0) {
                    ts->printf(cvtest::TS::LOG, "Marker detection failed");
                    ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                    return;
                }

                // interpolate charuco corners
                vector< Point2f > charucoCorners;
                vector< int > charucoIds;

                if(iter % 2 == 0) {
                    aruco::interpolateCornersCharuco(corners, ids, img, board, charucoCorners,
                                                     charucoIds);
                } else {
                    aruco::interpolateCornersCharuco(corners, ids, img, board, charucoCorners,
                                                     charucoIds, cameraMatrix, distCoeffs);
                }

                if(charucoIds.size() == 0) continue;

                // estimate charuco pose
                aruco::estimatePoseCharucoBoard(charucoCorners, charucoIds, board, cameraMatrix,
                                                distCoeffs, rvec, tvec);


                // check result
                vector< Point2f > projectedCharucoCorners;
                projectPoints(board->chessboardCorners, rvec, tvec, cameraMatrix, distCoeffs,
                              projectedCharucoCorners);

                for(unsigned int i = 0; i < charucoIds.size(); i++) {

                    int currentId = charucoIds[i];

                    if(currentId >= (int)board->chessboardCorners.size()) {
                        ts->printf(cvtest::TS::LOG, "Invalid Charuco corner id");
                        ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                        return;
                    }

                    double repError = cv::norm(charucoCorners[i] - projectedCharucoCorners[currentId]);  // TODO cvtest


                    if(repError > 5.) {
                        ts->printf(cvtest::TS::LOG, "Charuco corner reprojection error too high");
                        ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                        return;
                    }
                }
            }
        }
    }
}


/**
 * @brief Check diamond detection
 */
class CV_CharucoDiamondDetection : public cvtest::BaseTest {
    public:
    CV_CharucoDiamondDetection();

    protected:
    void run(int);
};


CV_CharucoDiamondDetection::CV_CharucoDiamondDetection() {}


void CV_CharucoDiamondDetection::run(int) {

    int iter = 0;
    Mat cameraMatrix = Mat::eye(3, 3, CV_64FC1);
    Size imgSize(500, 500);
    Ptr<aruco::Dictionary> dictionary = aruco::getPredefinedDictionary(aruco::DICT_6X6_250);
    float squareLength = 0.03f;
    float markerLength = 0.015f;
    Ptr<aruco::CharucoBoard> board =
        aruco::CharucoBoard::create(3, 3, squareLength, markerLength, dictionary);

    cameraMatrix.at< double >(0, 0) = cameraMatrix.at< double >(1, 1) = 650;
    cameraMatrix.at< double >(0, 2) = imgSize.width / 2;
    cameraMatrix.at< double >(1, 2) = imgSize.height / 2;

    Mat distCoeffs(5, 1, CV_64FC1, Scalar::all(0));
    // for different perspectives
    for(double distance = 0.3; distance <= 0.3; distance += 0.2) {
        for(int yaw = 0; yaw < 360; yaw += 100) {
            for(int pitch = 30; pitch <= 90; pitch += 30) {

                int markerBorder = iter % 2 + 1;
                for(int i = 0; i < 4; i++)
                    board->ids[i] = 4 * iter + i;
                iter++;

                // get synthetic image
                Mat rvec, tvec;
                Mat img = projectCharucoBoard(board, cameraMatrix, deg2rad(pitch), deg2rad(yaw),
                                              distance, imgSize, markerBorder, rvec, tvec);

                // detect markers
                vector< vector< Point2f > > corners;
                vector< int > ids;
                Ptr<aruco::DetectorParameters> params = aruco::DetectorParameters::create();
                params->minDistanceToBorder = 0;
                params->markerBorderBits = markerBorder;
                aruco::detectMarkers(img, dictionary, corners, ids, params);

                if(ids.size() != 4) {
                    ts->printf(cvtest::TS::LOG, "Not enough markers for diamond detection");
                    ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                    return;
                }

                // detect diamonds
                vector< vector< Point2f > > diamondCorners;
                vector< Vec4i > diamondIds;
                aruco::detectCharucoDiamond(img, corners, ids, squareLength / markerLength,
                                            diamondCorners, diamondIds, cameraMatrix, distCoeffs);

                // check results
                if(diamondIds.size() != 1) {
                    ts->printf(cvtest::TS::LOG, "Diamond not detected correctly");
                    ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                    return;
                }

                for(int i = 0; i < 4; i++) {
                    if(diamondIds[0][i] != board->ids[i]) {
                        ts->printf(cvtest::TS::LOG, "Incorrect diamond ids");
                        ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                        return;
                    }
                }


                vector< Point2f > projectedDiamondCorners;
                projectPoints(board->chessboardCorners, rvec, tvec, cameraMatrix, distCoeffs,
                              projectedDiamondCorners);

                vector< Point2f > projectedDiamondCornersReorder(4);
                projectedDiamondCornersReorder[0] = projectedDiamondCorners[2];
                projectedDiamondCornersReorder[1] = projectedDiamondCorners[3];
                projectedDiamondCornersReorder[2] = projectedDiamondCorners[1];
                projectedDiamondCornersReorder[3] = projectedDiamondCorners[0];


                for(unsigned int i = 0; i < 4; i++) {

                    double repError = cv::norm(diamondCorners[0][i] - projectedDiamondCornersReorder[i]);  // TODO cvtest

                    if(repError > 5.) {
                        ts->printf(cvtest::TS::LOG, "Diamond corner reprojection error too high");
                        ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                        return;
                    }
                }

                // estimate diamond pose
                vector< Vec3d > estimatedRvec, estimatedTvec;
                aruco::estimatePoseSingleMarkers(diamondCorners, squareLength, cameraMatrix,
                                                 distCoeffs, estimatedRvec, estimatedTvec);

                // check result
                vector< Point2f > projectedDiamondCornersPose;
                vector< Vec3f > diamondObjPoints(4);
                diamondObjPoints[0] = Vec3f(-squareLength / 2.f, squareLength / 2.f, 0);
                diamondObjPoints[1] = Vec3f(squareLength / 2.f, squareLength / 2.f, 0);
                diamondObjPoints[2] = Vec3f(squareLength / 2.f, -squareLength / 2.f, 0);
                diamondObjPoints[3] = Vec3f(-squareLength / 2.f, -squareLength / 2.f, 0);
                projectPoints(diamondObjPoints, estimatedRvec[0], estimatedTvec[0], cameraMatrix,
                              distCoeffs, projectedDiamondCornersPose);

                for(unsigned int i = 0; i < 4; i++) {
                    double repError = cv::norm(projectedDiamondCornersReorder[i] - projectedDiamondCornersPose[i]);  // TODO cvtest

                    if(repError > 5.) {
                        ts->printf(cvtest::TS::LOG, "Charuco pose error too high");
                        ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                        return;
                    }
                }
            }
        }
    }
}

/**
* @brief Check charuco board creation
*/
class CV_CharucoBoardCreation : public cvtest::BaseTest {
public:
    CV_CharucoBoardCreation();

protected:
    void run(int);
};

CV_CharucoBoardCreation::CV_CharucoBoardCreation() {}

void CV_CharucoBoardCreation::run(int)
{
    Ptr<aruco::Dictionary> dictionary = aruco::getPredefinedDictionary(aruco::DICT_5X5_250);
    int n = 6;

    float markerSizeFactor = 0.5f;

    for (float squareSize_mm = 5.0f; squareSize_mm < 35.0f; squareSize_mm += 0.1f)
    {
        Ptr<aruco::CharucoBoard> board_meters = aruco::CharucoBoard::create(
            n, n, squareSize_mm*1e-3f, squareSize_mm * markerSizeFactor * 1e-3f, dictionary);

        Ptr<aruco::CharucoBoard> board_millimeters = aruco::CharucoBoard::create(
            n, n, squareSize_mm, squareSize_mm * markerSizeFactor, dictionary);

        for (size_t i = 0; i < board_meters->nearestMarkerIdx.size(); i++)
        {
            if (board_meters->nearestMarkerIdx[i].size() != board_millimeters->nearestMarkerIdx[i].size() ||
                board_meters->nearestMarkerIdx[i][0] != board_millimeters->nearestMarkerIdx[i][0])
            {
                ts->printf(cvtest::TS::LOG,
                    cv::format("Charuco board topology is sensitive to scale with squareSize=%.1f\n",
                        squareSize_mm).c_str());
                ts->set_failed_test_info(cvtest::TS::FAIL_INVALID_OUTPUT);
                break;
            }
        }
    }
}


TEST(CV_CharucoDetection, accuracy) {
    CV_CharucoDetection test;
    test.safe_run();
}

TEST(CV_CharucoPoseEstimation, accuracy) {
    CV_CharucoPoseEstimation test;
    test.safe_run();
}

TEST(CV_CharucoDiamondDetection, accuracy) {
    CV_CharucoDiamondDetection test;
    test.safe_run();
}

TEST(CV_CharucoBoardCreation, accuracy) {
    CV_CharucoBoardCreation test;
    test.safe_run();
}

}} // namespace