boofcv.alg.feature.detect.chess

Class DetectChessSquaresBinary

java.lang.Object

boofcv.alg.feature.detect.chess.DetectChessSquaresBinary

public class DetectChessSquaresBinary
extends java.lang.Object

Given a binary image it detects the presence of chess board calibration grids. 1) Detect blobs in binary image and select square like ones. 2) Connect blobs based distance of corners. 3) prune graph. 4) sanity check graph structure. 5) Find bounding quadrilateral.

Constructor Summary

Constructors

Constructor and Description
DetectChessSquaresBinary(int numCols, int numRows, int minContourSize) Configures chess board detector.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	checkGraphStructure(java.util.List<QuadBlob> blobs) Counts the number of connections each node has.
static void	connect(java.util.List<QuadBlob> blobs) Connect blobs together based on corner distance.
georegression.struct.shapes.Polygon2D_I32	getBoundPolygon()
boofcv.struct.ImageRectangle	getBoundRect()
java.util.List<georegression.struct.point.Point2D_I32>	getCandidatePoints() Returns corners that are near a another square
DetectQuadBlobsBinary	getDetectBlobs()
java.util.List<QuadBlob>	getGraphBlobs()
boolean	process(boofcv.struct.image.ImageUInt8 binary) Detects chessboard in the binary image.
void	setMinimumContourSize(int minContourSize) Adjusts the minimum contour for a square blob

Methods inherited from class java.lang.Object

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

Constructor Detail

DetectChessSquaresBinary

public DetectChessSquaresBinary(int numCols,
                        int numRows,
                        int minContourSize)

Configures chess board detector.

Parameters:

numCols - Number of columns in square grid

numRows - Number of rows in square grid

minContourSize - Prune blobs which have a contour with few than this number of pixels.

Method Detail

process

public boolean process(boofcv.struct.image.ImageUInt8 binary)

Detects chessboard in the binary image. Square corners must be disconnected. Returns true if a chessboard was found, false otherwise.

Parameters:

binary - Binary image of chessboard

Returns:

True if successful.

connect

public static void connect(java.util.List<QuadBlob> blobs)

Connect blobs together based on corner distance. If two corners are uniquely close then connect them together.

checkGraphStructure

public boolean checkGraphStructure(java.util.List<QuadBlob> blobs)

Counts the number of connections each node has. If it is a legit grid then it should have a known number of nodes with a specific number of connections.

setMinimumContourSize

public void setMinimumContourSize(int minContourSize)

Adjusts the minimum contour for a square blob

Parameters:

minContourSize - The minimum contour size. Try 10

getDetectBlobs

public DetectQuadBlobsBinary getDetectBlobs()

getGraphBlobs

public java.util.List<QuadBlob> getGraphBlobs()

getBoundRect

public boofcv.struct.ImageRectangle getBoundRect()

getBoundPolygon

public georegression.struct.shapes.Polygon2D_I32 getBoundPolygon()

getCandidatePoints

public java.util.List<georegression.struct.point.Point2D_I32> getCandidatePoints()

Returns corners that are near a another square