# Package org.opencv.objdetect

- Class Summary
  Class | Description
  --- | ---
  ArucoDetector | The main functionality of ArucoDetector class is detection of markers in an image with detectMarkers() method.
  BarcodeDetector |
  Board | Board of ArUco markers A board is a set of markers in the 3D space with a common coordinate system.
  CharucoBoard | ChArUco board is a planar chessboard where the markers are placed inside the white squares of a chessboard.
  CharucoDetector |
  CharucoParameters |
  DetectorParameters | struct DetectorParameters is used by ArucoDetector
  Dictionary | Dictionary is a set of unique ArUco markers of the same size `bytesList` storing as 2-dimensions Mat with 4-th channels (CV_8UC4 type was used) and contains the marker codewords where: - bytesList.rows is the dictionary size - each marker is encoded using `nbytes = ceil(markerSize*markerSize/8.)` bytes - each row contains all 4 rotations of the marker, so its length is `4*nbytes` - the byte order in the bytesList[i] row: `//bytes without rotation/bytes with rotation 1/bytes with rotation 2/bytes with rotation 3//` So `bytesList.ptr(i)[k*nbytes + j]` is the j-th byte of i-th marker, in its k-th rotation.
  FaceDetectorYN | DNN-based face detector model download link: https://github.com/opencv/opencv_zoo/tree/master/models/face_detection_yunet
  FaceRecognizerSF | DNN-based face recognizer model download link: https://github.com/opencv/opencv_zoo/tree/master/models/face_recognition_sface
  GraphicalCodeDetector |
  GridBoard | Planar board with grid arrangement of markers More common type of board.
  Objdetect |
  QRCodeDetector | QR code detector.
  QRCodeDetectorAruco | QR code detector based on Aruco markers detection code.
  QRCodeDetectorAruco_Params |
  QRCodeEncoder | QR code encoder.
  QRCodeEncoder_Params | QR code encoder parameters.
  RefineParameters | struct RefineParameters is used by ArucoDetector