Module imagingbook.common

Package imagingbook.common.geometry.line

Class HessianLine

java.lang.Object

imagingbook.common.geometry.line.AlgebraicLine

imagingbook.common.geometry.line.HessianLine

All Implemented Interfaces:

Primitive2d, ShapeProducer

Direct Known Subclasses:

HoughLine

public class HessianLine
extends AlgebraicLine

This class represents a straight line in Hessian normal form, i.e., x * cos(angle) + y * sin(angle) = radius. It is merely a subclass of AlgebraicLine with a different constructor and getter methods for angle and radius. Instances are immutable. Reference point is (0,0). See Sec. 10.1 and Appendix F.1 of [1] for details.

[1] W. Burger, M.J. Burge, Digital Image Processing – An Algorithmic Introduction, 3rd ed, Springer (2022).

Version:

2022/11/18

Field Summary

Fields inherited from class imagingbook.common.geometry.line.AlgebraicLine

A, B, C

Constructor Summary

Constructors

Constructor	Description
HessianLine(double angle, double radius)	Constructor.
HessianLine(double a, double b, double c)
HessianLine(AlgebraicLine al)

Method Summary

Modifier and Type	Method	Description
static HessianLine	from(Pnt2d p1, Pnt2d p2)
double	getAngle()
double	getRadius()
String	toString()

Methods inherited from class imagingbook.common.geometry.line.AlgebraicLine

equals, equals, from, from, from, getClosestLinePoint, getDistance, getDistance, getParameters, getShape, getShape, getSignedDistance, getSignedDistance, getSquareError, getXref, getYref, intersect

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface imagingbook.common.geometry.shape.ShapeProducer

getShape, getShapes, getShapes

Constructor Details

HessianLine

public HessianLine(double angle,
 double radius)

Constructor. Creates a new HessianLine instance with the specified angle and radius. Note that this really creates a normalized AlgebraicLine. The values returned by getAngle() and getRadius() may not be identical to the values passed to this constructor.

Parameters:

angle - the line's angle

radius - the line's radius

HessianLine

public HessianLine(double a,
 double b,
 double c)

HessianLine

public HessianLine(AlgebraicLine al)

Method Details

from

public static HessianLine from(Pnt2d p1,
 Pnt2d p2)

getAngle

public double getAngle()

getRadius

public double getRadius()

toString

public String toString()

Overrides:

toString in class AlgebraicLine