ILCalibFFD Interface Reference

This interface provide functionalities of the FFD camera model. More...

Inheritance diagram for ILCalibFFD:

Public Member Functions
void	SetFFDGrid (int cols, int rows)
Public Member Functions inherited from ILCalib
LPVErrorCode	AddPoint (double imagePointX, double imagePointY, double worldPointX, double worldPointY)
LPVErrorCode	AddPoints (ILCalibPointPairs *pointPairs)
LPVErrorCode	Calibrate ()
LPVErrorCode	FixImage (ILImage *image, ILImage *fixedImage)
LPVErrorCode	GenPostTransformMatrix (ILCalibPointPairs *pointPairs)
void	ImageToWorld (double imagePointX, double imagePointY, double *worldPointX, double *worldPointY)
BOOL	IsCalibrated ()
void	SetImageSize (int w, int h)
void	SetPostTransform (double offsetX, double offsetY, double deltaAngle)
void	SetPostTransformMatrix (ILTransform *tf)
void	SetPostTransformMatrix23 (LMatrix23 *data)
void	SetPostTransformMatrix33 (LMatrix33 *data)
void	WorldToImage (double worldPointX, double worldPointY, double *imagePointX, double *imagePointY)
Public Member Functions inherited from ILObject
ILObject *	Copy ()
LPVErrorCode	Load (LString filename)
void	Reset ()
LPVErrorCode	Save (LString filename)
BOOL	Valid ()

Additional Inherited Members
Properties inherited from ILCalib
double	CalibError [get]
	The overall RMS re-projection error for the calibration, calculated based on the distances between the image points and the projected (using the optimized calibration matrices) world points. It's defined as: \( \sqrt{ \frac{1}{n} \sum_{i=0}^{n} distance(p^{image}_i, p^{proj}_i)^2 } \).
LPVFixImageMode	FixImageMode [get, set]
	The mode to fix image used in FixImage(). More...
double	FixImageOffsetX [get, set]
	The x-coordinate offset (in pixel unit) of the fixed image used in FixImage(), used together with FixImageOffsetY. By default, it's 0, means no offset in x-coordinate. You may change the offset to translate the fixed image, for example move the inspect region to the center of the fixed image.
double	FixImageOffsetY [get, set]
	The y-coordinate offset (in pixel unit) of the fixed image used in FixImage(), used together with FixImageOffsetX. By default, it's 0, means no offset in y-coordinate. You may change the offset to translate the fixed image, for example move the inspect region to the center of the fixed image.
double	FixImageScale [get, set]
	The scale of the fixed image used in FixImage(). By default, it's 1, means no scale. You may change the scale factor to zoom in/out the fixed image.
LPVInterpolationMethod	InterpolationMethod [get, set]
	The interpolation method used in fix the image for undistortion (and untilt). By default, it's LPVInterCubic.
LPVCalibModel	Model [get]
	The calibration model.
BOOL	UseCache [get, set]
	Whether to make use of cache which is used to speed-up the process of the image undistortion (and untilt), but consume more memory. By default, it's off.

Detailed Description

This interface provide functionalities of the FFD camera model.

In the FFD camera model, the calibration is represented as a free-form deformation grid from the image to world coordinates and also the reversed. Deformation grid is based on the parametric surface optimized from the provide image and world point pairs.
This model support all kinds of distortion.

To use this interface, you should create a LCalibFFD object.

Example Code

C++

ILCalibFFDPtr calib = LCalibFFD::Create();
calibBoard->Detect(img, &pntPairs);
calib->AddPoints(pntPairs);
calib->SetFFDGrid(4, 4); // use 4x4 FFD grid
LPVErrorCode err = calib->Calibrate();
if (err != LPVErrorCode::LPVNoError || !calib->IsCalibrated()) return;

C#

LCalibFFD calib = new LCalibFFD();
calibBoard.Detect(img, out pntPairs);
calib.AddPoints(pntPairs);
calib.SetFFDGrid(4, 4); // use 4x4 FFD grid
LPVErrorCode err = calib.Calibrate();
if (err != LPVErrorCode.LPVNoError || !calib.IsCalibrated()) return;

COM

ILCalibFFDPtr calib = LCalibFFD::Create();
// or, ILCalibFFDPtr calib(__uuidof(LCalibFFD)), for absence of built-in Create functions (before 2.2.0)
calibBoard->Detect(img, &pntPairs);
calib->AddPoints(pntPairs);
calib->SetFFDGrid(4, 4); // use 4x4 FFD grid
LPVErrorCode err = calib->Calibrate();
if (err != LPVErrorCode::LPVNoError || !calib->IsCalibrated()) return;

Member Function Documentation

SetFFDGrid()

void SetFFDGrid	(	int	cols,
		int	rows
	)

Set the size of FFD grid. By default, it's a \( 16 \times 16 \) grid.

Parameters

[in]	cols	The width of the FFD grid, in 2 ~ 64
[in]	rows	The height of the FFD grid, in 2 ~ 64