ILCameraArray Interface Reference

This interface provide functionalities of camera array generation, calibration and image stitching. More...

Inheritance diagram for ILCameraArray:

Public Member Functions
LPVErrorCode	Calibrate ()
void	ImageToWorld (double imagePointX, double imagePointY, double *worldPointX, double *worldPointY)
void	Init (LPVCalibModel calibModel, int hCount, int vCount)
void	InitByCopy (ILCalib *calib, int hCount, int vCount, BOOL copyCalib, double hStep, double vStep)
void	InitByCopyN (LArray< ILCalib * > calibs, int rows, int hCount, int vCount, BOOL copyCalib, double hStep, double vStep)
BOOL	IsCalibrated ()
ILCalib *	Item (int index)
LPVErrorCode	StitchImage (ILImageList *images, ILImage *stitchedImage)
void	WorldToImage (double worldPointX, double worldPointY, double *imagePointX, double *imagePointY)
Public Member Functions inherited from ILObjects
int	Count ()
BOOL	Empty ()
ILObject *	ItemObject (int objIndex)
Public Member Functions inherited from ILObject
ILObject *	Copy ()
LPVErrorCode	Load (LString filename)
void	Reset ()
LPVErrorCode	Save (LString filename)
BOOL	Valid ()

Properties
double	CalibError [get]
	The calibration error of the camera array, which is the maximum error among all calibration objects in it.
BOOL	EnableBlend [get, set]
	Whether to do blending in the overlap region of multiple views. By default, this feature is on. Enable it will output a more smooth image stitching result, but slower.
LPVInterpolationMethod	InterpolationMethod [get, set]
	The interpolation method used in stitching. By default, it's LPVInterCubic.
BOOL	UseCache [get, set]
	Whether to make use of cache which is used to speed-up the process of the image stitching (and blending), but consume more memory. By default, it's off.

Detailed Description

This interface provide functionalities of camera array generation, calibration and image stitching.

Camera array is a set of multiple independent cameras arranged on a known pattern, or one or multiple cameras moving along a fixed path which generate a virtual camera array. You can use this interface to create and manage the camera array, calibrate then stitch the images captured from individual cameras into a large image for preview or inspection.

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

Example Code

C++

ILCameraArrayPtr camArray = LCameraArray::Create();
camArray->Init(LPVCalibModel::LPVCalibPinHole, 2, 1); // generate a camera array with two cameras
// calibrate left and right camera individually
// ...
// calibrate the camera array
LPVErrorCode err = camArray->Calibrate();
if (err != LPVErrorCode::LPVNoError || !camArray->IsCalibrated()) {
    // something wrong
}
// image stitching
ILImageListPtr imgList = LImageList::Create();
imgList->Add(img1, nullptr);
imgList->Add(img2, nullptr);
camArray->StitchImage(imgList, imgStitched);

C#

LCameraArray camArray = new LCameraArray();
camArray.Init(LPVCalibModel.LPVCalibPinHole, 2, 1); // generate a camera array with two cameras
// calibrate left and right camera individually
// ...
// calibrate the camera array
LPVErrorCode err = camArray.Calibrate();
if (err != LPVErrorCode.LPVNoError || !camArray.IsCalibrated()) {
    // something wrong
}
// image stitching
LImageList imgList = new LImageList();
imgList.Add(img1);
imgList.Add(img2);
camArray.StitchImage(imgList, imgStitched);

COM

ILCameraArrayPtr camArray = LCameraArray::Create();
// or, ILCameraArrayPtr camArray(__uuidof(LCameraArray)), for absence of built-in Create functions (before 2.2.0)
camArray->Init(LPVCalibModel::LPVCalibPinHole, 2, 1); // generate a camera array with two cameras
// calibrate left and right camera individually
// ...
// calibrate the camera array
LPVErrorCode err = camArray->Calibrate();
if (err != LPVErrorCode::LPVNoError || !camArray->IsCalibrated()) {
    // something wrong
}
// image stitching
ILImageListPtr imgList = LImageList::Create();
// or, ILImageListPtr imgList(__uuidof(LImageList)), for absence of built-in Create functions (before 2.2.0)
imgList->Add(img1, NULL);
imgList->Add(img2, NULL);
camArray->StitchImage(imgList, imgStitched);

Member Function Documentation

Calibrate()

LPVErrorCode Calibrate

(

)

Do calibration with current configuration. Make sure individual views are calibrated, before doing camera array calibration.

Return values

error

Return error code if anything is wrong.

ImageToWorld()

void ImageToWorld	(	double	imagePointX,
		double	imagePointY,
		double *	worldPointX,
		double *	worldPointY
	)

Map a point from the stitching image coordinates to the world coordinates.
The mapping works with a calibrated system, if not the output world point is the same point as the input image point.

Parameters

[in]	imagePointX	The x-coordinate of the stitching image point.
[in]	imagePointY	The y-coordinate of the stitching image point.
[out]	worldPointX	Return the x-coordinate of the world point.
[out]	worldPointY	Return the y-coordinate of the world point.

Init()

void Init	(	LPVCalibModel	calibModel,
		int	hCount,
		int	vCount
	)

Initialize the camera array by \( vCount \times hCount \) cameras calibrated with the given calibration model.

Parameters

[in]	calibModel	The input camera calibration model.
[in]	hCount	The horizontal count of cameras, should be \( \ge 1 \) .
[in]	vCount	The vertical count of cameras, should be \( \ge 1 \) .

See also

InitByCopy(), InitByCopyN().

InitByCopy()

void InitByCopy	(	ILCalib *	calib,
		int	hCount,
		int	vCount,
		BOOL	copyCalib,
		double	hStep,
		double	vStep
	)

Initialize the camera array by moving one camera multiple times horizontally and vertically.
It generates a \( vCount \times hCount \) camera array.

Parameters

[in]	calib	The input camera calibration object to move.
[in]	hCount	The horizontal count of cameras, should be \( \ge 1 \) .
[in]	vCount	The vertical count of cameras, should be \( \ge 1 \) .
[in]	copyCalib	True to copy the calibration matrices. If the movement steps are also available, it will also help generate a post-transform matrix on each copied camera calibration object.
[in]	hStep	The distance of each horizontal movement, optional, in physical unit.
[in]	vStep	The distance of each vertical movement, optional, in physical unit.

See also

InitByCopyN().

InitByCopyN()

void InitByCopyN	(	LArray< ILCalib * >	calibs,
		int	rows,
		int	hCount,
		int	vCount,
		BOOL	copyCalib,
		double	hStep,
		double	vStep
	)

Similar as InitByCopy(), initialize the camera array by moving n cameras multiple times horizontally and vertically.
It generates a \( (vCount * rows) \times (hCount * n / rows) \) camera array.
For example, given 1 2 3 4 input cameras int two rows, move it 3 times horizontally and 2 times vertically, it results in a camera array as:

\( \begin{matrix}1 & 2 & 1 & 2 & 1 & 2\\3 & 4 & 3 & 4 & 3 & 4\\1 & 2 & 1 & 2 & 1 & 2\\3 & 4 & 3 & 4 & 3 & 4\end{matrix} \)

Parameters

[in]	calibs	The input collection of camera calibration objects.
[in]	rows	The count of rows of the input collection.
[in]	hCount	The horizontal count of cameras, should be \( \ge 1 \) .
[in]	vCount	The vertical count of cameras, should be \( \ge 1 \) .
[in]	copyCalib	True to copy the calibration matrices. If the movement steps are also available, it will also help generate a post-transform matrix on each copied camera calibration object.
[in]	hStep	The distance of each horizontal movement, optional, in physical unit.
[in]	vStep	The distance of each vertical movement, optional, in physical unit.

IsCalibrated()

BOOL IsCalibrated

(

)

Check whether the camera array and all calibration objects in it is well-calibrated.

Return values

val	Return true if it's calibrated, otherwise, return false.

Item()

ILCalib* Item

(

int

index

)

Fetch one camera calibration object with the given index.

Parameters

[in]

index

Input index, it should be a 0-based number smaller than total count.

Return values

calib

Return the camera calibration object.

StitchImage()

LPVErrorCode StitchImage	(	ILImageList *	images,
		ILImage *	stitchedImage
	)

Stitch the images from all cameras in the matrix.
The stitching works with a calibrated system, if not it returns the LPVErrCalibNotCalib error.

Parameters

[in]	images	The input image list, in the same order as the cameras row by row.
[out]	stitchedImage	The result image.

Return values

error

Return error code if anything is wrong.

WorldToImage()

void WorldToImage	(	double	worldPointX,
		double	worldPointY,
		double *	imagePointX,
		double *	imagePointY
	)

Map a point from the world coordinates to the stitching image coordinates.
The mapping works with a calibrated system, if not the output world point is the same point as the input image point.

Parameters

[in]	worldPointX	The x-coordinate of the world point.
[in]	worldPointY	The y-coordinate of the world point.
[out]	imagePointX	Return the x-coordinate of the stitching image point.
[out]	imagePointY	Return the y-coordinate of the stitching image point.