boofcv.alg.shapes.polygon

Class RefinePolygonLineToImage<T extends boofcv.struct.image.ImageSingleBand>

java.lang.Object

boofcv.alg.shapes.polygon.RefinePolygonLineToImage<T>

public class RefinePolygonLineToImage<T extends boofcv.struct.image.ImageSingleBand>
extends java.lang.Object

Improves the fits of a polygon's which is darker or lighter than the background. Polygon's edges are assumed to be perfectly straight lines. The edges are processed individually and fit to a line using weighted regression. Both black squares with white backgrounds and white shapes with black backgrounds can be found. The edges are selected to maximize the difference between light and dark regions.

For example, assume an image axis aligned rectangle has a lower extent of 1,2 and a upper extent of 12,15, is entirely filled, excluding the upper extent (as is typical). Then the found lower and upper extends of the found polygon will also be 1,2 and 12,15.

For input polygons which are in undistorted coordinates by with a distorted image call getSnapToEdge() and invoke BaseIntegralEdge.setTransform(PixelTransform_F32).

Field Summary

Fields

Modifier and Type	Field and Description
protected T	image

Constructor Summary

Constructors

Constructor and Description
RefinePolygonLineToImage(double cornerOffset, int lineSamples, int sampleRadius, int maxIterations, double convergeTolPixels, boolean fitBlack, java.lang.Class<T> imageType) Constructor which provides full access to all parameters.
RefinePolygonLineToImage(int numSides, boolean fitBlack, java.lang.Class<T> imageType) Simplified constructor which uses reasonable default values for most variables

Method Summary

Modifier and Type	Method and Description
SnapToEdge<T>	getSnapToEdge()
boolean	isFitBlack() True if it is fitting black to the image
protected boolean	optimize(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.
protected boolean	optimize(georegression.struct.shapes.Polygon2D_F64 seed, georegression.struct.shapes.Polygon2D_F64 current) Refines the initial line estimates using EM.
boolean	refine(georegression.struct.shapes.Polygon2D_F64 input, georegression.struct.shapes.Polygon2D_F64 output) Refines the fit a polygon by snapping it to the edges.
void	setImage(T image) Sets the image which is going to be processed.

Methods inherited from class java.lang.Object

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

Field Detail

image

protected T extends boofcv.struct.image.ImageSingleBand image

Constructor Detail

RefinePolygonLineToImage

public RefinePolygonLineToImage(double cornerOffset,
                                int lineSamples,
                                int sampleRadius,
                                int maxIterations,
                                double convergeTolPixels,
                                boolean fitBlack,
                                java.lang.Class<T> imageType)

Constructor which provides full access to all parameters. See code documents value a description of these variables.

RefinePolygonLineToImage

public RefinePolygonLineToImage(int numSides,
                                boolean fitBlack,
                                java.lang.Class<T> imageType)

Simplified constructor which uses reasonable default values for most variables

Parameters:

numSides - Number of sides on the polygon

fitBlack - If true it's fitting a black square with a white background. false is the inverse.

imageType - Type of input image it processes

Method Detail

setImage

public void setImage(T image)

Sets the image which is going to be processed. If a transform is to be used BaseIntegralEdge.setTransform(boofcv.struct.distort.PixelTransform_F32) should be called before this.

refine

public boolean refine(georegression.struct.shapes.Polygon2D_F64 input,
                      georegression.struct.shapes.Polygon2D_F64 output)

Refines the fit a polygon by snapping it to the edges.

Parameters:

input - (input) Initial estimate for the polygon. Vertexes must be in clockwise order.

output - (output) the fitted polygon

optimize

protected boolean optimize(georegression.struct.shapes.Polygon2D_F64 seed,
                           georegression.struct.shapes.Polygon2D_F64 current)

Refines the initial line estimates using EM. The number of iterations is fixed.

optimize

protected boolean optimize(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

Parameters:

a - Corner point in image coordinates.

b - Corner point in image coordinates.

found - (output) Line in image coordinates

Returns:

true if successful or false if it failed

getSnapToEdge

public SnapToEdge<T> getSnapToEdge()

isFitBlack

public boolean isFitBlack()

True if it is fitting black to the image