ILLineDetector Interface Reference

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

Inheritance diagram for ILLineDetector:

Public Member Functions
LPVErrorCode	Detect (ILImage *img, ILRotRectRegion *region, ILLineResults **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 line. You may pick a proper score with help of line score chart. More...
int	EdgeWidth [get, set]
	The edge width of the line 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 lines if there's more than expected line candidates.
int	MaxCount [get, set]
	The maximum of lines 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 line detection.

Line detector is designed to locate a single or multiple line edges in given image and along the region's direction.
The algorithm is real-time and of sub-pixel accuracy, while the limitation is it could only detect parallel lines with small angle range (-10, +10) relative to the region's direction. So, to use this detector, you should have a basic idea of the target lines' direction.

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

Example Code

C++

ILLineDetectorPtr lineDetector = LLineDetector::Create();
lineDetector->Polarity = LPVPolarity::LPVPolarityEitherEdge;
LPVErrorCode err = lineDetector->Detect(img, roi, &lineResults);
if (err != LPVErrorCode::LPVNoError) return;

C#

LLineDetector lineDetector = new LLineDetector();
lineDetector.Polarity = LPVPolarity.LPVPolarityEitherEdge;
LPVErrorCode err = lineDetector.Detect(img, (LRotRectRegion)roi, out lineResults);
if (err != LPVErrorCode.LPVNoError) return;

COM

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

Member Function Documentation

Detect()

LPVErrorCode Detect	(	ILImage *	img,
		ILRotRectRegion *	region,
		ILLineResults **	results
	)

Detect lines using the line detector.

Parameters

[in]	img	The input image.
[in]	region	The input region, it should be a rotated rectangle region with its direction well-defined.
[out]	results	Return the line 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 line. You may pick a proper score with help of line score chart.

See also

ILLineResults::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