// This file is part of OpenCV project. // It is subject to the license terms in the LICENSE file found in the top-level directory // of this distribution and at http://opencv.org/license.html #include "../precomp.hpp" #include #include "opencv2/objdetect/aruco_board.hpp" #include #include namespace cv { namespace aruco { using namespace std; struct Board::Impl { Dictionary dictionary; std::vector ids; std::vector > objPoints; Point3f rightBottomBorder; explicit Impl(const Dictionary& _dictionary): dictionary(_dictionary) {} virtual ~Impl() {} Impl(const Impl&) = delete; Impl& operator=(const Impl&) = delete; virtual void matchImagePoints(InputArrayOfArrays detectedCorners, InputArray detectedIds, OutputArray _objPoints, OutputArray imgPoints) const; virtual void generateImage(Size outSize, OutputArray img, int marginSize, int borderBits) const; }; void Board::Impl::matchImagePoints(InputArrayOfArrays detectedCorners, InputArray detectedIds, OutputArray _objPoints, OutputArray imgPoints) const { CV_Assert(detectedIds.total() == detectedCorners.total()); CV_Assert(detectedIds.total() > 0ull); CV_Assert(detectedCorners.depth() == CV_32F); size_t nDetectedMarkers = detectedIds.total(); vector objPnts; objPnts.reserve(nDetectedMarkers); vector imgPnts; imgPnts.reserve(nDetectedMarkers); // look for detected markers that belong to the board and get their information Mat detectedIdsMat = detectedIds.getMat(); vector detectedCornersVecMat; detectedCorners.getMatVector(detectedCornersVecMat); CV_Assert((int)detectedCornersVecMat.front().total()*detectedCornersVecMat.front().channels() == 8); for(unsigned int i = 0; i < nDetectedMarkers; i++) { int currentId = detectedIdsMat.at(i); for(unsigned int j = 0; j < ids.size(); j++) { if(currentId == ids[j]) { for(int p = 0; p < 4; p++) { objPnts.push_back(objPoints[j][p]); imgPnts.push_back(detectedCornersVecMat[i].ptr(0)[p]); } } } } // create output Mat(objPnts).copyTo(_objPoints); Mat(imgPnts).copyTo(imgPoints); } void Board::Impl::generateImage(Size outSize, OutputArray img, int marginSize, int borderBits) const { CV_Assert(!outSize.empty()); CV_Assert(marginSize >= 0); img.create(outSize, CV_8UC1); Mat out = img.getMat(); out.setTo(Scalar::all(255)); out.adjustROI(-marginSize, -marginSize, -marginSize, -marginSize); // calculate max and min values in XY plane CV_Assert(objPoints.size() > 0); float minX, maxX, minY, maxY; minX = maxX = objPoints[0][0].x; minY = maxY = objPoints[0][0].y; for(unsigned int i = 0; i < objPoints.size(); i++) { for(int j = 0; j < 4; j++) { minX = min(minX, objPoints[i][j].x); maxX = max(maxX, objPoints[i][j].x); minY = min(minY, objPoints[i][j].y); maxY = max(maxY, objPoints[i][j].y); } } float sizeX = maxX - minX; float sizeY = maxY - minY; // now paint each marker Mat marker; Point2f outCorners[3]; Point2f inCorners[3]; for(unsigned int m = 0; m < objPoints.size(); m++) { // transform corners to markerZone coordinates for(int j = 0; j < 3; j++) { Point2f pf = Point2f(objPoints[m][j].x, objPoints[m][j].y); // move top left to 0, 0 pf -= Point2f(minX, minY); pf.x = pf.x / sizeX * float(out.cols); pf.y = pf.y / sizeY * float(out.rows); outCorners[j] = pf; } // get marker Size dst_sz(outCorners[2] - outCorners[0]); // assuming CCW order dst_sz.width = dst_sz.height = std::min(dst_sz.width, dst_sz.height); //marker should be square dictionary.generateImageMarker(ids[m], dst_sz.width, marker, borderBits); if((outCorners[0].y == outCorners[1].y) && (outCorners[1].x == outCorners[2].x)) { // marker is aligned to image axes marker.copyTo(out(Rect(outCorners[0], dst_sz))); continue; } // interpolate tiny marker to marker position in markerZone inCorners[0] = Point2f(-0.5f, -0.5f); inCorners[1] = Point2f(marker.cols - 0.5f, -0.5f); inCorners[2] = Point2f(marker.cols - 0.5f, marker.rows - 0.5f); // remove perspective Mat transformation = getAffineTransform(inCorners, outCorners); warpAffine(marker, out, transformation, out.size(), INTER_LINEAR, BORDER_TRANSPARENT); } } Board::Board(const Ptr& _impl): impl(_impl) { CV_Assert(impl); } Board::Board(): impl(nullptr) {} Board::Board(InputArrayOfArrays objPoints, const Dictionary &dictionary, InputArray ids): Board(new Board::Impl(dictionary)) { CV_Assert(objPoints.total() == ids.total()); CV_Assert(objPoints.type() == CV_32FC3 || objPoints.type() == CV_32FC1); vector > obj_points_vector; Point3f rightBottomBorder = Point3f(0.f, 0.f, 0.f); for (unsigned int i = 0; i < objPoints.total(); i++) { vector corners; Mat corners_mat = objPoints.getMat(i); if (corners_mat.type() == CV_32FC1) corners_mat = corners_mat.reshape(3); CV_Assert(corners_mat.total() == 4); for (int j = 0; j < 4; j++) { const Point3f &corner = corners_mat.at(j); corners.push_back(corner); rightBottomBorder.x = std::max(rightBottomBorder.x, corner.x); rightBottomBorder.y = std::max(rightBottomBorder.y, corner.y); rightBottomBorder.z = std::max(rightBottomBorder.z, corner.z); } obj_points_vector.push_back(corners); } ids.copyTo(impl->ids); impl->objPoints = obj_points_vector; impl->rightBottomBorder = rightBottomBorder; } const Dictionary& Board::getDictionary() const { CV_Assert(this->impl); return this->impl->dictionary; } const vector >& Board::getObjPoints() const { CV_Assert(this->impl); return this->impl->objPoints; } const Point3f& Board::getRightBottomCorner() const { CV_Assert(this->impl); return this->impl->rightBottomBorder; } const vector& Board::getIds() const { CV_Assert(this->impl); return this->impl->ids; } /** @brief Implementation of draw planar board that accepts a raw Board pointer. */ void Board::generateImage(Size outSize, OutputArray img, int marginSize, int borderBits) const { CV_Assert(this->impl); impl->generateImage(outSize, img, marginSize, borderBits); } void Board::matchImagePoints(InputArrayOfArrays detectedCorners, InputArray detectedIds, OutputArray objPoints, OutputArray imgPoints) const { CV_Assert(this->impl); impl->matchImagePoints(detectedCorners, detectedIds, objPoints, imgPoints); } struct GridBoardImpl : public Board::Impl { GridBoardImpl(const Dictionary& _dictionary, const Size& _size, float _markerLength, float _markerSeparation): Board::Impl(_dictionary), size(_size), markerLength(_markerLength), markerSeparation(_markerSeparation), legacyPattern(false) { CV_Assert(size.width*size.height > 0 && markerLength > 0 && markerSeparation > 0); } // number of markers in X and Y directions const Size size; // marker side length (normally in meters) float markerLength; // separation between markers in the grid float markerSeparation; // set pre4.6.0 chessboard pattern behavior (even row count patterns have a white box in the upper left corner) bool legacyPattern; }; GridBoard::GridBoard() {} GridBoard::GridBoard(const Size& size, float markerLength, float markerSeparation, const Dictionary &dictionary, InputArray ids): Board(new GridBoardImpl(dictionary, size, markerLength, markerSeparation)) { float onePin = markerLength / ((float)(dictionary.markerSize+2)); if (markerSeparation < onePin*.7f) { CV_LOG_WARNING(NULL, "Marker border " << markerSeparation << " is less than 70% of ArUco pin size " << onePin << ". Please increase markerSeparation or decrease markerLength for stable board detection"); } size_t totalMarkers = (size_t) size.width*size.height; CV_Assert(ids.empty() || totalMarkers == ids.total()); vector > objPoints; objPoints.reserve(totalMarkers); if(!ids.empty()) { ids.copyTo(impl->ids); } else { impl->ids = std::vector(totalMarkers); std::iota(impl->ids.begin(), impl->ids.end(), 0); } // calculate Board objPoints for (int y = 0; y < size.height; y++) { for (int x = 0; x < size.width; x++) { vector corners(4); corners[0] = Point3f(x * (markerLength + markerSeparation), y * (markerLength + markerSeparation), 0); corners[1] = corners[0] + Point3f(markerLength, 0, 0); corners[2] = corners[0] + Point3f(markerLength, markerLength, 0); corners[3] = corners[0] + Point3f(0, markerLength, 0); objPoints.push_back(corners); } } impl->objPoints = objPoints; impl->rightBottomBorder = Point3f(size.width * markerLength + markerSeparation * (size.width - 1), size.height * markerLength + markerSeparation * (size.height - 1), 0.f); } Size GridBoard::getGridSize() const { CV_Assert(impl); return static_pointer_cast(impl)->size; } float GridBoard::getMarkerLength() const { CV_Assert(impl); return static_pointer_cast(impl)->markerLength; } float GridBoard::getMarkerSeparation() const { CV_Assert(impl); return static_pointer_cast(impl)->markerSeparation; } struct CharucoBoardImpl : Board::Impl { CharucoBoardImpl(const Dictionary& _dictionary, const Size& _size, float _squareLength, float _markerLength): Board::Impl(_dictionary), size(_size), squareLength(_squareLength), markerLength(_markerLength), legacyPattern(false) {} // chessboard size Size size; // Physical size of chessboard squares side (normally in meters) float squareLength; // Physical marker side length (normally in meters) float markerLength; // set pre4.6.0 chessboard pattern behavior (even row count patterns have a white box in the upper left corner) bool legacyPattern; // vector of chessboard 3D corners precalculated std::vector chessboardCorners; // for each charuco corner, nearest marker index in ids array std::vector > nearestMarkerIdx; // for each charuco corner, nearest marker corner id of each marker std::vector > nearestMarkerCorners; void createCharucoBoard(); void calcNearestMarkerCorners(); void matchImagePoints(InputArrayOfArrays detectedCharuco, InputArray detectedIds, OutputArray objPoints, OutputArray imgPoints) const override; void generateImage(Size outSize, OutputArray img, int marginSize, int borderBits) const override; }; void CharucoBoardImpl::createCharucoBoard() { float diffSquareMarkerLength = (squareLength - markerLength) / 2; int totalMarkers = (int)(ids.size()); // calculate Board objPoints int nextId = 0; objPoints.clear(); for(int y = 0; y < size.height; y++) { for(int x = 0; x < size.width; x++) { if(legacyPattern && (size.height % 2 == 0)) { // legacy behavior only for even row count patterns if((y + 1) % 2 == x % 2) continue; // black corner, no marker here } else { if(y % 2 == x % 2) continue; // black corner, no marker here } vector corners(4); corners[0] = Point3f(x * squareLength + diffSquareMarkerLength, y * squareLength + diffSquareMarkerLength, 0); corners[1] = corners[0] + Point3f(markerLength, 0, 0); corners[2] = corners[0] + Point3f(markerLength, markerLength, 0); corners[3] = corners[0] + Point3f(0, markerLength, 0); objPoints.push_back(corners); // first ids in dictionary if (totalMarkers == 0) ids.push_back(nextId); nextId++; } } if (totalMarkers > 0 && nextId != totalMarkers) CV_Error(cv::Error::StsBadSize, "Size of ids must be equal to the number of markers: "+std::to_string(nextId)); // now fill chessboardCorners chessboardCorners.clear(); for(int y = 0; y < size.height - 1; y++) { for(int x = 0; x < size.width - 1; x++) { Point3f corner; corner.x = (x + 1) * squareLength; corner.y = (y + 1) * squareLength; corner.z = 0; chessboardCorners.push_back(corner); } } rightBottomBorder = Point3f(size.width * squareLength, size.height * squareLength, 0.f); calcNearestMarkerCorners(); } /** Fill nearestMarkerIdx and nearestMarkerCorners arrays */ void CharucoBoardImpl::calcNearestMarkerCorners() { nearestMarkerIdx.clear(); nearestMarkerCorners.clear(); nearestMarkerIdx.resize(chessboardCorners.size()); nearestMarkerCorners.resize(chessboardCorners.size()); unsigned int nMarkers = (unsigned int)objPoints.size(); unsigned int nCharucoCorners = (unsigned int)chessboardCorners.size(); for(unsigned int i = 0; i < nCharucoCorners; i++) { double minDist = -1; // distance of closest markers Point3f charucoCorner = chessboardCorners[i]; for(unsigned int j = 0; j < nMarkers; j++) { // calculate distance from marker center to charuco corner Point3f center = Point3f(0, 0, 0); for(unsigned int k = 0; k < 4; k++) center += objPoints[j][k]; center /= 4.; double sqDistance; Point3f distVector = charucoCorner - center; sqDistance = distVector.x * distVector.x + distVector.y * distVector.y; if(j == 0 || fabs(sqDistance - minDist) < cv::pow(0.01 * squareLength, 2)) { // if same minimum distance (or first iteration), add to nearestMarkerIdx vector nearestMarkerIdx[i].push_back(j); minDist = sqDistance; } else if(sqDistance < minDist) { // if finding a closest marker to the charuco corner nearestMarkerIdx[i].clear(); // remove any previous added marker nearestMarkerIdx[i].push_back(j); // add the new closest marker index minDist = sqDistance; } } // for each of the closest markers, search the marker corner index closer // to the charuco corner for(unsigned int j = 0; j < nearestMarkerIdx[i].size(); j++) { nearestMarkerCorners[i].resize(nearestMarkerIdx[i].size()); double minDistCorner = -1; for(unsigned int k = 0; k < 4; k++) { double sqDistance; Point3f distVector = charucoCorner - objPoints[nearestMarkerIdx[i][j]][k]; sqDistance = distVector.x * distVector.x + distVector.y * distVector.y; if(k == 0 || sqDistance < minDistCorner) { // if this corner is closer to the charuco corner, assing its index // to nearestMarkerCorners minDistCorner = sqDistance; nearestMarkerCorners[i][j] = k; } } } } } void CharucoBoardImpl::matchImagePoints(InputArrayOfArrays detectedCharuco, InputArray detectedIds, OutputArray outObjPoints, OutputArray outImgPoints) const { CV_CheckEQ(detectedIds.total(), detectedCharuco.total(), "Number of corners and ids must be equal"); CV_Assert(detectedIds.total() > 0ull); CV_Assert(detectedCharuco.depth() == CV_32F); // detectedCharuco includes charuco corners as vector or Mat. // Python bindings could add extra dimension to detectedCharuco and therefore vector case is additionally processed. CV_Assert((detectedCharuco.isMat() || detectedCharuco.isVector() || detectedCharuco.isMatVector() || detectedCharuco.isUMatVector()) && detectedCharuco.depth() == CV_32F); size_t nDetected = detectedCharuco.total(); vector objPnts(nDetected); vector imgPnts(nDetected); Mat detectedCharucoMat, detectedIdsMat = detectedIds.getMat(); if (!detectedCharuco.isMatVector()) { detectedCharucoMat = detectedCharuco.getMat(); CV_Assert(detectedCharucoMat.checkVector(2)); } std::vector detectedCharucoVecMat; if (detectedCharuco.isMatVector()) { detectedCharuco.getMatVector(detectedCharucoVecMat); } for(size_t i = 0ull; i < nDetected; i++) { int pointId = detectedIdsMat.at((int)i); CV_Assert(pointId >= 0 && pointId < (int)chessboardCorners.size()); objPnts[i] = chessboardCorners[pointId]; if (detectedCharuco.isMatVector()) { CV_Assert((int)detectedCharucoVecMat[i].total() * detectedCharucoVecMat[i].channels() == 2); imgPnts[i] = detectedCharucoVecMat[i].ptr(0)[0]; } else imgPnts[i] = detectedCharucoMat.ptr(0)[i]; } Mat(objPnts).copyTo(outObjPoints); Mat(imgPnts).copyTo(outImgPoints); } void CharucoBoardImpl::generateImage(Size outSize, OutputArray img, int marginSize, int borderBits) const { CV_Assert(!outSize.empty()); CV_Assert(marginSize >= 0); img.create(outSize, CV_8UC1); img.setTo(255); Mat out = img.getMat(); Mat noMarginsImg = out.colRange(marginSize, out.cols - marginSize).rowRange(marginSize, out.rows - marginSize); // the size of the chessboard square depends on the location of the chessboard float pixInSquare = 0.f; // the size of the chessboard in pixels Size pixInChessboard(noMarginsImg.cols, noMarginsImg.rows); // determine the zone where the chessboard is placed float pixInSquareX = (float)noMarginsImg.cols / (float)size.width; float pixInSquareY = (float)noMarginsImg.rows / (float)size.height; Point startChessboard(0, 0); if (pixInSquareX <= pixInSquareY) { // the width of "noMarginsImg" image determines the dimensions of the chessboard pixInSquare = pixInSquareX; pixInChessboard.height = cvRound(pixInSquare*size.height); int rowsMargin = (noMarginsImg.rows - pixInChessboard.height) / 2; startChessboard.y = rowsMargin; } else { // the height of "noMarginsImg" image determines the dimensions of the chessboard pixInSquare = pixInSquareY; pixInChessboard.width = cvRound(pixInSquare*size.width); int colsMargin = (noMarginsImg.cols - pixInChessboard.width) / 2; startChessboard.x = colsMargin; } // determine the zone where the chessboard is located Mat chessboardZoneImg = noMarginsImg(Rect(startChessboard, pixInChessboard)); // marker size in pixels const float pixInMarker = markerLength/squareLength*pixInSquare; // the size of the marker margin in pixels const float pixInMarginMarker = 0.5f*(pixInSquare - pixInMarker); // determine the zone where the aruco markers are located int endArucoX = cvRound(pixInSquare*(size.width-1)+pixInMarginMarker+pixInMarker); int endArucoY = cvRound(pixInSquare*(size.height-1)+pixInMarginMarker+pixInMarker); Mat arucoZone = chessboardZoneImg(Range(cvRound(pixInMarginMarker), endArucoY), Range(cvRound(pixInMarginMarker), endArucoX)); // draw markers Board::Impl::generateImage(arucoZone.size(), arucoZone, 0, borderBits); // now draw black squares for(int y = 0; y < size.height; y++) { for(int x = 0; x < size.width; x++) { if(legacyPattern && (size.height % 2 == 0)) { // legacy behavior only for even row count patterns if((y + 1) % 2 != x % 2) continue; // white corner, dont do anything } else { if(y % 2 != x % 2) continue; // white corner, dont do anything } float startX = pixInSquare * float(x); float startY = pixInSquare * float(y); Mat squareZone = chessboardZoneImg(Range(cvRound(startY), cvRound(startY + pixInSquare)), Range(cvRound(startX), cvRound(startX + pixInSquare))); squareZone.setTo(0); } } } CharucoBoard::CharucoBoard(){} CharucoBoard::CharucoBoard(const Size& size, float squareLength, float markerLength, const Dictionary &dictionary, InputArray ids): Board(new CharucoBoardImpl(dictionary, size, squareLength, markerLength)) { CV_Assert(size.width > 1 && size.height > 1 && markerLength > 0 && squareLength > markerLength); float onePin = markerLength / ((float)(dictionary.markerSize+2)); float markerSeparation = (squareLength - markerLength)/2.f; if (markerSeparation < onePin*.7f) { CV_LOG_WARNING(NULL, "Marker border " << markerSeparation << " is less than 70% of ArUco pin size " << onePin <<". Please increase markerSeparation or decrease markerLength for stable board detection"); } ids.copyTo(impl->ids); static_pointer_cast(impl)->createCharucoBoard(); } Size CharucoBoard::getChessboardSize() const { CV_Assert(impl); return static_pointer_cast(impl)->size; } float CharucoBoard::getSquareLength() const { CV_Assert(impl); return static_pointer_cast(impl)->squareLength; } float CharucoBoard::getMarkerLength() const { CV_Assert(impl); return static_pointer_cast(impl)->markerLength; } void CharucoBoard::setLegacyPattern(bool legacyPattern) { CV_Assert(impl); if (static_pointer_cast(impl)->legacyPattern != legacyPattern) { static_pointer_cast(impl)->legacyPattern = legacyPattern; static_pointer_cast(impl)->createCharucoBoard(); } } bool CharucoBoard::getLegacyPattern() const { CV_Assert(impl); return static_pointer_cast(impl)->legacyPattern; } bool CharucoBoard::checkCharucoCornersCollinear(InputArray charucoIds) const { CV_Assert(impl); Mat charucoIdsMat = charucoIds.getMat(); unsigned int nCharucoCorners = (unsigned int)charucoIdsMat.total(); if (nCharucoCorners <= 2) return true; // only test if there are 3 or more corners auto board = static_pointer_cast(impl); CV_Assert(board->chessboardCorners.size() >= charucoIdsMat.total()); Vec point0(board->chessboardCorners[charucoIdsMat.at(0)].x, board->chessboardCorners[charucoIdsMat.at(0)].y, 1); Vec point1(board->chessboardCorners[charucoIdsMat.at(1)].x, board->chessboardCorners[charucoIdsMat.at(1)].y, 1); // create a line from the first two points. Vec testLine = point0.cross(point1); Vec testPoint(0, 0, 1); double divisor = sqrt(testLine[0]*testLine[0] + testLine[1]*testLine[1]); CV_Assert(divisor != 0.0); // normalize the line with normal testLine /= divisor; double dotProduct; for (unsigned int i = 2; i < nCharucoCorners; i++){ testPoint(0) = board->chessboardCorners[charucoIdsMat.at(i)].x; testPoint(1) = board->chessboardCorners[charucoIdsMat.at(i)].y; // if testPoint is on testLine, dotProduct will be zero (or very, very close) dotProduct = testPoint.dot(testLine); if (std::abs(dotProduct) > 1e-6){ return false; } } // no points found that were off of testLine, return true that all points collinear. return true; } std::vector CharucoBoard::getChessboardCorners() const { CV_Assert(impl); return static_pointer_cast(impl)->chessboardCorners; } std::vector > CharucoBoard::getNearestMarkerIdx() const { CV_Assert(impl); return static_pointer_cast(impl)->nearestMarkerIdx; } std::vector > CharucoBoard::getNearestMarkerCorners() const { CV_Assert(impl); return static_pointer_cast(impl)->nearestMarkerCorners; } } }