Class FastLineDetector

Class implementing the FLD (Fast Line Detector) algorithm described in @cite Lee14.

Inheritance

System.Object

DisposableObject

DisposableCvObject

Algorithm

FastLineDetector

Implements

ICvPtrHolder

Inherited Members

Algorithm.Write(FileStorage)

Algorithm.Read(FileNode)

Algorithm.Empty

Algorithm.Save(String)

Algorithm.GetDefaultName()

DisposableCvObject.ptr

DisposableCvObject.DisposeUnmanaged()

DisposableCvObject.CvPtr

DisposableObject.DataHandle

DisposableObject.IsDisposed

DisposableObject.IsEnabledDispose

DisposableObject.AllocatedMemory

DisposableObject.AllocatedMemorySize

DisposableObject.Dispose()

DisposableObject.Dispose(Boolean)

DisposableObject.AllocGCHandle(Object)

DisposableObject.AllocMemory(Int32)

DisposableObject.NotifyMemoryPressure(Int64)

DisposableObject.ThrowIfDisposed()

Namespace: OpenCvSharp.XImgProc

Assembly: OpenCvSharp.dll

Syntax

public class FastLineDetector : Algorithm, ICvPtrHolder

Constructors

FastLineDetector(IntPtr)

Creates instance by raw pointer

Declaration

protected FastLineDetector(IntPtr p)

Parameters

Type	Name	Description
IntPtr	p

Methods

Create(Int32, Single, Double, Double, Int32, Boolean)

Creates a smart pointer to a FastLineDetector object and initializes it

Declaration

public static FastLineDetector Create(int lengthThreshold = 10, float distanceThreshold = 1.41421354F, double cannyTh1 = 50, double cannyTh2 = 50, int cannyApertureSize = 3, bool doMerge = false)

Parameters

Type	Name	Description
System.Int32	lengthThreshold	Segment shorter than this will be discarded
System.Single	distanceThreshold	A point placed from a hypothesis line segment farther than this will be regarded as an outlier
System.Double	cannyTh1	First threshold for hysteresis procedure in Canny()
System.Double	cannyTh2	Second threshold for hysteresis procedure in Canny()
System.Int32	cannyApertureSize	Aperturesize for the sobel operator in Canny()
System.Boolean	doMerge	If true, incremental merging of segments will be perfomred

Returns

Type	Description
FastLineDetector

Detect(InputArray)

Finds lines in the input image. This is the output of the default parameters of the algorithm on the above shown image.

Declaration

public virtual Vec4f[] Detect(InputArray image)

Parameters

Type	Name	Description
InputArray	image	A grayscale (CV_8UC1) input image. If only a roi needs to be selected, use: fld_ptr-\>detect(image(roi), lines, ...); lines += Scalar(roi.x, roi.y, roi.x, roi.y);

Returns

Type	Description
Vec4f[]	A vector of Vec4f elements specifying the beginning and ending point of a line. Where Vec4f is (x1, y1, x2, y2), point 1 is the start, point 2 - end.Returned lines are directed so that the brighter side is on their left.

Detect(InputArray, OutputArray)

Finds lines in the input image. This is the output of the default parameters of the algorithm on the above shown image.

Declaration

public virtual void Detect(InputArray image, OutputArray lines)

Parameters

Type	Name	Description
InputArray	image	A grayscale (CV_8UC1) input image. If only a roi needs to be selected, use: fld_ptr-\>detect(image(roi), lines, ...); lines += Scalar(roi.x, roi.y, roi.x, roi.y);
OutputArray	lines	A vector of Vec4f elements specifying the beginning and ending point of a line. Where Vec4f is (x1, y1, x2, y2), point 1 is the start, point 2 - end.Returned lines are directed so that the brighter side is on their left.

DisposeManaged()

Releases managed resources

Declaration

protected override void DisposeManaged()

Overrides

DisposableObject.DisposeManaged()

DrawSegments(InputOutputArray, IEnumerable<Vec4f>, Boolean)

Draws the line segments on a given image.

Declaration

public virtual void DrawSegments(InputOutputArray image, IEnumerable<Vec4f> lines, bool drawArrow = false)

Parameters

Type	Name	Description
InputOutputArray	image	The image, where the lines will be drawn. Should be bigger or equal to the image, where the lines were found.
IEnumerable<Vec4f>	lines	A vector of the lines that needed to be drawn.
System.Boolean	drawArrow	If true, arrow heads will be drawn.

DrawSegments(InputOutputArray, InputArray, Boolean)

Draws the line segments on a given image.

Declaration

public virtual void DrawSegments(InputOutputArray image, InputArray lines, bool drawArrow = false)

Parameters

Type	Name	Description
InputOutputArray	image	The image, where the lines will be drawn. Should be bigger or equal to the image, where the lines were found.
InputArray	lines	A vector of the lines that needed to be drawn.
System.Boolean	drawArrow	If true, arrow heads will be drawn.

Implements

ICvPtrHolder