org.opencv.objdetect

Class CharucoBoard

java.lang.Object

org.opencv.objdetect.Board

org.opencv.objdetect.CharucoBoard

public class CharucoBoard
extends Board

ChArUco board is a planar chessboard where the markers are placed inside the white squares of a chessboard. The benefits of ChArUco boards is that they provide both, ArUco markers versatility and chessboard corner precision, which is important for calibration and pose estimation. The board image can be drawn using generateImage() method.

Constructor Summary

Constructors

Constructor and Description
CharucoBoard(Size size, float squareLength, float markerLength, Dictionary dictionary) CharucoBoard constructor
CharucoBoard(Size size, float squareLength, float markerLength, Dictionary dictionary, Mat ids) CharucoBoard constructor

Method Summary

Modifier and Type	Method and Description
static CharucoBoard	__fromPtr__(long addr)
boolean	checkCharucoCornersCollinear(Mat charucoIds) check whether the ChArUco markers are collinear
MatOfPoint3f	getChessboardCorners() get CharucoBoard::chessboardCorners
Size	getChessboardSize()
boolean	getLegacyPattern()
float	getMarkerLength()
float	getSquareLength()
void	setLegacyPattern(boolean legacyPattern) set legacy chessboard pattern.

Methods inherited from class org.opencv.objdetect.Board

generateImage, generateImage, generateImage, getDictionary, getIds, getNativeObjAddr, getObjPoints, getRightBottomCorner, matchImagePoints

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CharucoBoard

public CharucoBoard(Size size,
                    float squareLength,
                    float markerLength,
                    Dictionary dictionary)

CharucoBoard constructor

Parameters:

size - number of chessboard squares in x and y directions

squareLength - squareLength chessboard square side length (normally in meters)

markerLength - marker side length (same unit than squareLength)

dictionary - dictionary of markers indicating the type of markers The first markers in the dictionary are used to fill the white chessboard squares.

CharucoBoard

public CharucoBoard(Size size,
                    float squareLength,
                    float markerLength,
                    Dictionary dictionary,
                    Mat ids)

CharucoBoard constructor

Parameters:

size - number of chessboard squares in x and y directions

squareLength - squareLength chessboard square side length (normally in meters)

markerLength - marker side length (same unit than squareLength)

dictionary - dictionary of markers indicating the type of markers

ids - array of id used markers The first markers in the dictionary are used to fill the white chessboard squares.

Method Detail

__fromPtr__

public static CharucoBoard __fromPtr__(long addr)

checkCharucoCornersCollinear

public boolean checkCharucoCornersCollinear(Mat charucoIds)

check whether the ChArUco markers are collinear

Parameters:

charucoIds - list of identifiers for each corner in charucoCorners per frame.

Returns:

bool value, 1 (true) if detected corners form a line, 0 (false) if they do not. solvePnP, calibration functions will fail if the corners are collinear (true). The number of ids in charucoIDs should be <= the number of chessboard corners in the board. This functions checks whether the charuco corners are on a straight line (returns true, if so), or not (false). Axis parallel, as well as diagonal and other straight lines detected. Degenerate cases: for number of charucoIDs <= 2,the function returns true.

getChessboardCorners

public MatOfPoint3f getChessboardCorners()

get CharucoBoard::chessboardCorners

Returns:

automatically generated

getChessboardSize

public Size getChessboardSize()

getLegacyPattern

public boolean getLegacyPattern()

getMarkerLength

public float getMarkerLength()

getSquareLength

public float getSquareLength()

setLegacyPattern

public void setLegacyPattern(boolean legacyPattern)

set legacy chessboard pattern. Legacy setting creates chessboard patterns starting with a white box in the upper left corner if there is an even row count of chessboard boxes, otherwise it starts with a black box. This setting ensures compatibility to patterns created with OpenCV versions prior OpenCV 4.6.0. See https://github.com/opencv/opencv/issues/23152. Default value: false.

Parameters:

legacyPattern - automatically generated