org.opencv.objdetect

Class Board

java.lang.Object

org.opencv.objdetect.Board

Direct Known Subclasses:

CharucoBoard, GridBoard

public class Board
extends Object

Board of ArUco markers A board is a set of markers in the 3D space with a common coordinate system. The common form of a board of marker is a planar (2D) board, however any 3D layout can be used. A Board object is composed by: - The object points of the marker corners, i.e. their coordinates respect to the board system. - The dictionary which indicates the type of markers of the board - The identifier of all the markers in the board.

Field Summary

Fields

Modifier and Type	Field and Description
protected long	nativeObj

Constructor Summary

Constructors

Modifier	Constructor and Description
	Board(List<Mat> objPoints, Dictionary dictionary, Mat ids) Common Board constructor
protected	Board(long addr)

Method Summary

Modifier and Type	Method and Description
static Board	__fromPtr__(long addr)
protected void	finalize()
void	generateImage(Size outSize, Mat img) Draw a planar board
void	generateImage(Size outSize, Mat img, int marginSize) Draw a planar board
void	generateImage(Size outSize, Mat img, int marginSize, int borderBits) Draw a planar board
Dictionary	getDictionary() return the Dictionary of markers employed for this board
MatOfInt	getIds() vector of the identifiers of the markers in the board (should be the same size as objPoints)
long	getNativeObjAddr()
List<MatOfPoint3f>	getObjPoints() return array of object points of all the marker corners in the board.
Point3	getRightBottomCorner() get coordinate of the bottom right corner of the board, is set when calling the function create()
void	matchImagePoints(List<Mat> detectedCorners, Mat detectedIds, Mat objPoints, Mat imgPoints) Given a board configuration and a set of detected markers, returns the corresponding image points and object points, can be used in solvePnP()

Methods inherited from class java.lang.Object

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

Field Detail

nativeObj

protected final long nativeObj

Constructor Detail

Board

protected Board(long addr)

Board

public Board(List<Mat> objPoints,
             Dictionary dictionary,
             Mat ids)

Common Board constructor

Parameters:

objPoints - array of object points of all the marker corners in the board

dictionary - the dictionary of markers employed for this board

ids - vector of the identifiers of the markers in the board

Method Detail

getNativeObjAddr

public long getNativeObjAddr()

__fromPtr__

public static Board __fromPtr__(long addr)

getDictionary

public Dictionary getDictionary()

return the Dictionary of markers employed for this board

Returns:

automatically generated

getObjPoints

public List<MatOfPoint3f> getObjPoints()

return array of object points of all the marker corners in the board. Each marker include its 4 corners in this order: - objPoints[i][0] - left-top point of i-th marker - objPoints[i][1] - right-top point of i-th marker - objPoints[i][2] - right-bottom point of i-th marker - objPoints[i][3] - left-bottom point of i-th marker Markers are placed in a certain order - row by row, left to right in every row. For M markers, the size is Mx4.

Returns:

automatically generated

getIds

public MatOfInt getIds()

vector of the identifiers of the markers in the board (should be the same size as objPoints)

Returns:

vector of the identifiers of the markers

getRightBottomCorner

public Point3 getRightBottomCorner()

get coordinate of the bottom right corner of the board, is set when calling the function create()

Returns:

automatically generated

matchImagePoints

public void matchImagePoints(List<Mat> detectedCorners,
                             Mat detectedIds,
                             Mat objPoints,
                             Mat imgPoints)

Given a board configuration and a set of detected markers, returns the corresponding image points and object points, can be used in solvePnP()

Parameters:

detectedCorners - List of detected marker corners of the board. For cv::Board and cv::GridBoard the method expects std::vector<std::vector<Point2f>> or std::vector<Mat> with Aruco marker corners. For cv::CharucoBoard the method expects std::vector<Point2f> or Mat with ChAruco corners (chess board corners matched with Aruco markers).

detectedIds - List of identifiers for each marker or charuco corner. For any Board class the method expects std::vector<int> or Mat.

objPoints - Vector of marker points in the board coordinate space. For any Board class the method expects std::vector<cv::Point3f> objectPoints or cv::Mat

imgPoints - Vector of marker points in the image coordinate space. For any Board class the method expects std::vector<cv::Point2f> objectPoints or cv::Mat SEE: solvePnP

generateImage

public void generateImage(Size outSize,
                          Mat img,
                          int marginSize,
                          int borderBits)

Draw a planar board

Parameters:

outSize - size of the output image in pixels.

img - output image with the board. The size of this image will be outSize and the board will be on the center, keeping the board proportions.

marginSize - minimum margins (in pixels) of the board in the output image

borderBits - width of the marker borders. This function return the image of the board, ready to be printed.

generateImage

public void generateImage(Size outSize,
                          Mat img,
                          int marginSize)

Draw a planar board

Parameters:

outSize - size of the output image in pixels.

img - output image with the board. The size of this image will be outSize and the board will be on the center, keeping the board proportions.

marginSize - minimum margins (in pixels) of the board in the output image This function return the image of the board, ready to be printed.

generateImage

public void generateImage(Size outSize,
                          Mat img)

Draw a planar board

Parameters:

outSize - size of the output image in pixels.

img - output image with the board. The size of this image will be outSize and the board will be on the center, keeping the board proportions. This function return the image of the board, ready to be printed.

finalize

protected void finalize()
                 throws Throwable

Overrides:

finalize in class Object

Throws:

Throwable