ILCircleDetector Interface Reference

This interface provide functionalities of circle detection. More...

Inheritance diagram for ILCircleDetector:

Public Member Functions
LPVErrorCode	Detect (ILImage *img, ILAnnulusRegion *region, ILCircleResults **results)
Public Member Functions inherited from ILObject
ILObject *	Copy ()
LPVErrorCode	Load (LString filename)
void	Reset ()
LPVErrorCode	Save (LString filename)
BOOL	Valid ()

Properties
int	AcceptScore [get, set]
	The accept score used in detection. It defines the minimum score for identifying the edge as a good circle. You may pick a proper score with help of circle score chart. More...
int	EdgeWidth [get, set]
	The edge width of the circle used in detection, in 1 ~ 10. Edge width defines the count of pixels along the whole edge transition. Blurred edge indicates larger edge width value to find a stable result. Usually, it's fine to just use default setting (3).
LPVFindBy	FindBy [get, set]
	The detection searching strategy. It defines how to select the result circles if there's more than expected circle candidates.
int	MaxCount [get, set]
	The maximum of circles to find.
BOOL	NormScore [get, set]
	Whether we should normalize the score based on maximum gradient in region.
LPVPolarity	Polarity [get, set]
	The detection edge polarity. Polarity defines the edge transition according to region's direction, black pixels are dark, white pixels are light. More...

Detailed Description

This interface provide functionalities of circle detection.

Circle detector is designed to locate a single or multiple circle edges in given image and inside the annulus region.
The algorithm is real-time and of sub-pixel accuracy, while the limitation is it could only detect concentric circles whose center is near the center of the annulus region. So, to use this detector, you should have a basic idea of the target circles' center and size.

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

Example Code

C++

ILCircleDetectorPtr circleDetector = LCircleDetector::Create();
circleDetector->Polarity = LPVPolarity::LPVPolarityEitherEdge;
LPVErrorCode err = circleDetector->Detect(img, roi, &circleResults);
if (err != LPVErrorCode::LPVNoError) return;

C#

LCircleDetector circleDetector = new LCircleDetector();
circleDetector.Polarity = LPVPolarity.LPVPolarityEitherEdge;
LPVErrorCode err = circleDetector.Detect(img, (LRotRectRegion)roi, out circleResults);
if (err != LPVErrorCode.LPVNoError) return;

COM

ILCircleDetectorPtr circleDetector = LCircleDetector::Create();
// or, ILCircleDetectorPtr circleDetector(__uuidof(LCircleDetector)), for absence of built-in Create functions (before 2.2.0)
circleDetector->Polarity = LPVPolarity::LPVPolarityEitherEdge;
LPVErrorCode err = circleDetector->Detect(img, roi, &circleResults);
if (err != LPVErrorCode::LPVNoError) return;

Member Function Documentation

Detect()

LPVErrorCode Detect	(	ILImage *	img,
		ILAnnulusRegion *	region,
		ILCircleResults **	results
	)

Detect circles using the circle detector.

Parameters

[in]	img	The input image.
[in]	region	Input region, it should be a annulus region placed near the estimated circle center. Pass in null to use the center of the image as the estimated circle center.
[out]	results	Return the circle results.

Return values

error

Return error code if anything is wrong.

Property Documentation

AcceptScore

int AcceptScore

getset

The accept score used in detection. It defines the minimum score for identifying the edge as a good circle. You may pick a proper score with help of circle score chart.

See also

ILCircleResults::DrawScoreChart().

Polarity

LPVPolarity Polarity

getset

The detection edge polarity.
Polarity defines the edge transition according to region's direction, black pixels are dark, white pixels are light.

See also

FindBy, EdgeWidth