mimas::camera_calibration::corner_detection

mimas::camera_calibration::corner_detection Class Reference
[Camera Calibration]

Class to find the corners of the chessboard accurately using a template algorithm. More...

#include <corner_detection.h>

Collaboration diagram for mimas::camera_calibration::corner_detection:


Public Types
typedef boost::numeric::ublas::matrix< point_f >	MatrixPoint
	a matrix of points
typedef boost::numeric::ublas::matrix< pixel_f >	MatrixPixel
	a matrix of pixels
typedef boost::numeric::ublas::matrix< double >	Matrix
	a matrix of doubles
typedef rgba< unsigned char >	pixel_rgba
	a pixel
Public Member Functions
	corner_detection (int size_x, int size_y, int size_window, pixel_rgba white, pixel_rgba black)
	Constructor.
	~corner_detection (void)
	Destructor.
void	findCorners (image< pixel_rgba > img, std::vector< pixel_f > pix, double min_corr) throw (mimasexception)
	Finds the corners of an chessboard, given the 4 extreme corners.
MatrixPixel	getCorners ()
	Returns the matrix of the found corners.

Detailed Description

Class to find the corners of the chessboard accurately using a template algorithm.

The algorithm, given the 4 extreme corners, computes an homography in order to get a first approximation of all the corners, and then searches for the corner in a square window around the approximation.

Author:: Julien Faucher (faucherj@gmail.com)

Definition at line 37 of file corner_detection.h.

Member Typedef Documentation

typedef boost::numeric::ublas::matrix< point_f > mimas::camera_calibration::corner_detection::MatrixPoint

a matrix of points

Definition at line 41 of file corner_detection.h.

typedef boost::numeric::ublas::matrix< pixel_f > mimas::camera_calibration::corner_detection::MatrixPixel

a matrix of pixels

Definition at line 44 of file corner_detection.h.

typedef boost::numeric::ublas::matrix< double > mimas::camera_calibration::corner_detection::Matrix

a matrix of doubles

Definition at line 47 of file corner_detection.h.

typedef rgba< unsigned char > mimas::camera_calibration::corner_detection::pixel_rgba

a pixel

Definition at line 50 of file corner_detection.h.

Constructor & Destructor Documentation

mimas::camera_calibration::corner_detection::corner_detection	(	int	size_x,
		int	size_y,
		int	size_window,
		pixel_rgba	white,
		pixel_rgba	black
	)

Constructor.

Initializes the template of the cross for the correlation algorithm

Parameters:

	size_x	width of the chessboard (number of black squares)
	size_y	height of the chessboard (number of black squares)
	size_window	the size of the square to look for the corners (the parameter is half the size of an edge of the square)
	white	the value of a white pixel on the picture
	black	the value of a black pixel on the picture

mimas::camera_calibration::corner_detection::~corner_detection ( void )

Destructor.

Member Function Documentation

void mimas::camera_calibration::corner_detection::findCorners	(	image< pixel_rgba >	img,
		std::vector< pixel_f >	pix,
		double	min_corr
	)			throw (mimasexception)

Finds the corners of an chessboard, given the 4 extreme corners.

This function computes with the extrem corners an homography in order to get a first approximation of the corner locations, and uses the detection algorithm in a window around the approximed pixel, to get the accurate one.

Parameters:

	img	the mimas image
	pix	a std::vector of the 4 extreme corners
	min_corr	the minimum correlation to be calculated to assume that the result is accurate. 0.85 or 0.90 seem to be good values.