boofcv.alg.shapes.polyline

Class RefinePolyLineCorner

java.lang.Object

boofcv.alg.shapes.polyline.RefinePolyLineCorner

public class RefinePolyLineCorner
extends java.lang.Object

Optimizing corner placements to a pixel level when given a contour and integer list of approximate corner locations which define set of line segments. Corners are optimized by searching for another near by pixel in the provided contour which reduces the distance of the contour from the line segments. This is intended to optimize the output from SplitMergeLineFit. Can be configured to handle case where line segments form a loop or have disconnected end points.

Each corner is individually optimized once per iteration. The process is repeated until the maximum number of iterations has been reached or there is no change in corner placements.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	searchRadius

Constructor Summary

Constructors

Constructor and Description
RefinePolyLineCorner(boolean looping) Constructor using default parameters
RefinePolyLineCorner(boolean looping, int maxIterations) Constructor with configurable parameters

Method Summary

Modifier and Type	Method and Description
protected double	computeCost(java.util.List<georegression.struct.point.Point2D_I32> contour, int c0, int c1, int c2, int offset) Computes the distance between the two lines defined by corner points in the contour
protected static double	distance(georegression.struct.line.LineGeneral2D_F64 line, georegression.struct.point.Point2D_I32 p) If A*A + B*B == 1 then a simplified distance formula can be used
protected double	distanceSum(georegression.struct.line.LineGeneral2D_F64 line, int c0, int c1, java.util.List<georegression.struct.point.Point2D_I32> contour) Sum of Euclidean distance of contour points along the line
boolean	fit(java.util.List<georegression.struct.point.Point2D_I32> contour, org.ddogleg.struct.GrowQueue_I32 corners) Fits a polygon to the contour given an initial set of candidate corners.
protected int	optimize(java.util.List<georegression.struct.point.Point2D_I32> contour, int c0, int c1, int c2) Searches around the current c1 point for the best place to put the corner

Methods inherited from class java.lang.Object

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

Field Detail

searchRadius

protected int searchRadius

Constructor Detail

RefinePolyLineCorner

public RefinePolyLineCorner(boolean looping,
                            int maxIterations)

Constructor with configurable parameters

Parameters:

looping - true if it loops or false if not

maxIterations - Number of internal EM iterations

RefinePolyLineCorner

public RefinePolyLineCorner(boolean looping)

Constructor using default parameters

Method Detail

fit

public boolean fit(java.util.List<georegression.struct.point.Point2D_I32> contour,
                   org.ddogleg.struct.GrowQueue_I32 corners)

Fits a polygon to the contour given an initial set of candidate corners. If not looping the corners must include the end points still. Minimum of 3 points required. Otherwise there's no corner!.

Parameters:

contour - Contours around the shape

corners - (Input) initial set of corners. (output) refined set of corners

optimize

protected int optimize(java.util.List<georegression.struct.point.Point2D_I32> contour,
                       int c0,
                       int c1,
                       int c2)

Searches around the current c1 point for the best place to put the corner

Returns:

location of best corner in local search region

computeCost

protected double computeCost(java.util.List<georegression.struct.point.Point2D_I32> contour,
                             int c0,
                             int c1,
                             int c2,
                             int offset)

Computes the distance between the two lines defined by corner points in the contour

Parameters:

contour - list of contour points

c0 - end point of line 0

c1 - start of line 0 and 1

c2 - end point of line 1

offset - added to c1 to make start of lines

Returns:

sum of distance of points along contour

distanceSum

protected double distanceSum(georegression.struct.line.LineGeneral2D_F64 line,
                             int c0,
                             int c1,
                             java.util.List<georegression.struct.point.Point2D_I32> contour)

Sum of Euclidean distance of contour points along the line

distance

protected static double distance(georegression.struct.line.LineGeneral2D_F64 line,
                                 georegression.struct.point.Point2D_I32 p)

If A*A + B*B == 1 then a simplified distance formula can be used