org.openimaj.image.camera.calibration

Class ChessboardCornerFinder

java.lang.Object

org.openimaj.image.camera.calibration.ChessboardCornerFinder

All Implemented Interfaces:

ImageAnalyser<FImage>

public class ChessboardCornerFinder
extends Object
implements ImageAnalyser<FImage>

This is a port/reworking of the OpenCV chessboard corner finder algorithm to OpenIMAJ. The key image-processing and geometry algorithms use the OpenIMAJ equivalents, but the code to extract the board and assess the correctness is purely based on a (slightly sanitised) port of the original OpenCV code.

This is improved variant of chessboard corner detection algorithm that uses a graph of connected quads. It is based on the code contributed by Vladimir Vezhnevets and Philip Gruebele. Here is the copyright notice from the original Vladimir's code:

The algorithms developed and implemented by Vezhnevets Vldimir aka Dead Moroz (vvp@graphics.cs.msu.ru) See http://graphics.cs.msu.su/en/research/calibration/opencv.html for detailed information.

Reliability additions and modifications made by Philip Gruebele.

Some further improvements for detection of partially occluded boards at non-ideal lighting conditions have been made by Alex Bovyrin and Kurt Kolonige.

Author:

Jonathon Hare (jsh2@ecs.soton.ac.uk)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ChessboardCornerFinder.Options Options for controlling how the corner finder works

Constructor Summary

Constructors

Constructor and Description
ChessboardCornerFinder(int patternWidth, int patternHeight, ChessboardCornerFinder.Options... opts) Construct with the given pattern size and options set.

Method Summary

Modifier and Type	Method and Description
void	analyseImage(FImage image) Analyse an image.
void	drawChessboardCorners(MBFImage image) Draw the predicted chessboard corners from the last call to analyseImage(FImage) on the given image.
static void	drawChessboardCorners(MBFImage image, int patternWidth, int patternHeight, List<? extends Point2d> corners, boolean found) Draw the given chessboard corners from on the given image.
List<Point2dImpl>	getCorners() Get any corners detected by the last call to analyseImage(FImage).
boolean	isFound() Was a chessboard found in the last call to analyseImage(FImage)?
static void	main(String[] args) Simple test program

Methods inherited from class java.lang.Object

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

Constructor Detail

ChessboardCornerFinder

public ChessboardCornerFinder(int patternWidth,
                              int patternHeight,
                              ChessboardCornerFinder.Options... opts)

Construct with the given pattern size and options set.

Parameters:

patternWidth - the pattern width

patternHeight - the pattern height

opts - the options

Method Detail

analyseImage

public void analyseImage(FImage image)

Description copied from interface: ImageAnalyser

Analyse an image.

Specified by:

analyseImage in interface ImageAnalyser<FImage>

Parameters:

image - The image to process in place.

isFound

public boolean isFound()

Was a chessboard found in the last call to analyseImage(FImage)?

Returns:

true if found; false otherwise

getCorners

public List<Point2dImpl> getCorners()

Get any corners detected by the last call to analyseImage(FImage).

Returns:

the corners

drawChessboardCorners

public void drawChessboardCorners(MBFImage image)

Draw the predicted chessboard corners from the last call to analyseImage(FImage) on the given image.

Parameters:

image - the image to draw on

drawChessboardCorners

public static void drawChessboardCorners(MBFImage image,
                                         int patternWidth,
                                         int patternHeight,
                                         List<? extends Point2d> corners,
                                         boolean found)

Draw the given chessboard corners from on the given image.

Parameters:

image - the image to draw on

patternWidth - the chessboard pattern width

patternHeight - the chessboard pattern height

corners - the corners

found - true if the corners were found

main

public static void main(String[] args)
                 throws IOException

Simple test program

Parameters:

args -

Throws:

IOException