boofcv.alg.shapes.edge

Class SnapToEdge<T extends boofcv.struct.image.ImageGray>

java.lang.Object

boofcv.alg.shapes.edge.BaseIntegralEdge<T>

boofcv.alg.shapes.edge.SnapToEdge<T>

public class SnapToEdge<T extends boofcv.struct.image.ImageGray>
extends BaseIntegralEdge<T>

Snaps a line to an edge of an object. The refined line attempts to maximize the absolute value of the difference between the left and right sides of the line.

The algorithm works by sampling along the provided line segment. For each point along the line it also samples points tangential to it in the left and right direction. When a point is sampled it is actually the line integral between two points which are one pixel apart. The weight is found as the absolute value of difference the between two adjacent line integrals along the tangent.

Internally it will compute the solution in a local coordinate system to reduce numerical errors.

DISTORTED INPUT IMAGE: If the distortion is known it is possible to sample along a straight line in distorted image space. This can be accomplished through the use of BaseIntegralEdge.setTransform(boofcv.struct.distort.PixelTransform_F32) where the provided transform goes from undistorted pixel coordinates into the distorted input image.

Field Summary

Fields

Modifier and Type	Field and Description
protected georegression.struct.point.Point2D_F64	center
protected int	lineSamples
protected double	localScale
protected int	radialSamples
protected org.ddogleg.struct.FastQueue<georegression.struct.point.Point2D_F64>	samplePts
protected org.ddogleg.struct.GrowQueue_F64	weights

Fields inherited from class boofcv.alg.shapes.edge.BaseIntegralEdge

integral, integralImage

Constructor Summary

Constructors

Constructor and Description
SnapToEdge(int lineSamples, int tangentialSamples, java.lang.Class<T> imageType) Configures the algorithm.

Method Summary

Modifier and Type	Method and Description
protected void	computePointsAndWeights(double slopeX, double slopeY, double x0, double y0, double tanX, double tanY) Computes the location of points along the line and their weights
java.lang.Class<T>	getImageType()
int	getLineSamples()
int	getRadialSamples()
protected void	localToGlobal(georegression.struct.line.LineGeneral2D_F64 line) Converts the line from local to global image coordinates
boolean	refine(georegression.struct.point.Point2D_F64 a, georegression.struct.point.Point2D_F64 b, georegression.struct.line.LineGeneral2D_F64 found) Fits a line defined by the two points.
void	setImageType(java.lang.Class<T> imageType)
void	setLineSamples(int lineSamples)
void	setRadialSamples(int radialSamples)

Methods inherited from class boofcv.alg.shapes.edge.BaseIntegralEdge

setImage, setTransform

Methods inherited from class java.lang.Object

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

Field Detail

lineSamples

protected int lineSamples

radialSamples

protected int radialSamples

weights

protected org.ddogleg.struct.GrowQueue_F64 weights

samplePts

protected org.ddogleg.struct.FastQueue<georegression.struct.point.Point2D_F64> samplePts

center

protected georegression.struct.point.Point2D_F64 center

localScale

protected double localScale

Constructor Detail

SnapToEdge

public SnapToEdge(int lineSamples,
                  int tangentialSamples,
                  java.lang.Class<T> imageType)

Configures the algorithm.

Parameters:

lineSamples - Number of times it will sample along the line's axis. Try 19

tangentialSamples - Radius along the tangent of what it will sample. Must be ≥ 1. Try 2.

imageType - Type of image it's going to process

Method Detail

refine

public boolean refine(georegression.struct.point.Point2D_F64 a,
                      georegression.struct.point.Point2D_F64 b,
                      georegression.struct.line.LineGeneral2D_F64 found)

Fits a line defined by the two points. When fitting the line the weight of the edge is used to determine. how influential the point is. Multiple calls might be required to get a perfect fit.

Parameters:

a - Start of line

b - End of line..

found - (output) Fitted line to the edge

Returns:

true if successful or false if it failed

computePointsAndWeights

protected void computePointsAndWeights(double slopeX,
                                       double slopeY,
                                       double x0,
                                       double y0,
                                       double tanX,
                                       double tanY)

Computes the location of points along the line and their weights

localToGlobal

protected void localToGlobal(georegression.struct.line.LineGeneral2D_F64 line)

Converts the line from local to global image coordinates

getLineSamples

public int getLineSamples()

setLineSamples

public void setLineSamples(int lineSamples)

getRadialSamples

public int getRadialSamples()

setRadialSamples

public void setRadialSamples(int radialSamples)

getImageType

public java.lang.Class<T> getImageType()

setImageType

public void setImageType(java.lang.Class<T> imageType)