de.unihalle.informatik.MiToBo.morphology

Class DistanceTransform

java.lang.Object

de.unihalle.informatik.Alida.operator.ALDOperator

de.unihalle.informatik.MiToBo.core.operator.MTBOperator

de.unihalle.informatik.MiToBo.morphology.DistanceTransform

All Implemented Interfaces:

de.unihalle.informatik.Alida.datatypes.ALDConfigurationValidator, de.unihalle.informatik.Alida.operator.events.ALDOperatorExecutionProgressEventListener, EventListener

@ALDAOperator(genericExecutionMode=ALL,
              level=APPLICATION)
public class DistanceTransform
extends MTBOperator

Calculate Champfer distance transform with optional precursor infos.

 
 Class to calculate a distance map / field from a binary image using the
 Champfer algorithm from
 
 G. Borgefors, "Distance transformations in digital images", Computer
 Vision, Graphics, and Image Processing, vol. 34, pp. 344–371, 1986.
 
 Several distance metrics (Euclide, Chessboard, Cityblock) and the foreground
 (0 for black and 1 for white) can be specified. A 8-way neighborhood is used.
 
 NOTE!
 The distance is calculated for each background pixel to the nearest
 foreground pixel. For example, if the distance should be calculated inside a
 white object, the black background should be set as foreground color.
 
 The distance field is created as MTBImage or as a two dimensional double 
 array. First dimension specifies the y-coordinate of the field, and the
 second dimension specifies the x-coordinate of the field.
 
 

Optionally this class offers as additional information a map of the precursor pixels for each position, i.e. the pixel which lead to the actual distance value, and a map containing for each background pixel the object pixel being closest to the pixel according to the distances calculated during the transformation.

Note that if precursor information is extracted the distance transform runs slightly less efficient than the original one since the two additional maps are filled during the calculations and more memory is required for them.

Author:

misiak, moeller

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DistanceTransform.DistanceMetric Several distance metrics.
static class	DistanceTransform.ForegroundColor Color of binary image foreground.

Nested classes/interfaces inherited from class de.unihalle.informatik.Alida.operator.ALDOperator

de.unihalle.informatik.Alida.operator.ALDOperator.HidingMode, de.unihalle.informatik.Alida.operator.ALDOperator.HistoryConstructionMode

Field Summary

Fields

Modifier and Type	Field and Description
private Point2D.Double[][]	closestObjectPixelMap Map of closest object pixels for each background location.
private MTBImage	distanceImg The distance field as MTBImage.
private double[][]	distanceMap The distance field as two-dimensional double array.
private DistanceTransform.DistanceMetric	distanceMetric Distance metric to apply.
private boolean	extractPrecursorInfos Flag to enable/disable extraction of precursor infos.
private DistanceTransform.ForegroundColor	foreground Foreground color of the foreground object.
private int	height Height of the given image.
private MTBImageByte	inputImage Binary input image.
private Point2D.Double[][]	precursorMap Map of precursor positions for each pixel in the background.
private int	width Width of the given image.

Fields inherited from class de.unihalle.informatik.Alida.operator.ALDOperator

completeDAG, name, operatorExecutionEventlistenerList, portHashAccess, verbose, versionProvider

Constructor Summary

Constructors

Constructor and Description
DistanceTransform() Standard constructor.
DistanceTransform(MTBImageByte image, DistanceTransform.DistanceMetric dm, DistanceTransform.ForegroundColor fg) Constructor to create a new DistanceTransform object.

Method Summary

Modifier and Type	Method and Description
private void	calcDM() Method to calculate the distance map of the given binary image using the Chamfer-algorithm.
Point2D.Double[][]	getClosestObjectPixelMap() Get the calculated map of closest object pixels.
MTBImage	getDistanceImage() Get the calculated distance map image.
double[][]	getDistanceMap() Get the calculated distance map.
DistanceTransform.DistanceMetric	getDistMetric() Get the used distance metric.
DistanceTransform.ForegroundColor	getForeground() Get the used foreground color.
int	getHeight() Get image height.
MTBImageByte	getInImg() Get the input image.
Point2D.Double[][]	getPrecursorMap() Get the calculated precursor map.
int	getWidth() Get image width.
protected void	operate()
void	setDistMetric(DistanceTransform.DistanceMetric metric) Set the distance metric.
void	setForeground(DistanceTransform.ForegroundColor fColor) Set the foreground color.
void	setInImg(MTBImageByte inImg) Set the input image.
void	setPrecursorInfosEnabled(boolean f) Enable or disable extraction of additional precursor infos.

Methods inherited from class de.unihalle.informatik.MiToBo.core.operator.MTBOperator

readResolve

Methods inherited from class de.unihalle.informatik.Alida.operator.ALDOperator

addOperatorExecutionProgressEventListener, addParameter, addParameter, addParameterUnconditioned, fieldContained, fireOperatorExecutionProgressEvent, getALDPortHashAccessKey, getConstructionMode, getDocumentation, getHidingMode, getInactiveParameterNames, getInInoutNames, getInInoutNames, getInNames, getInOutNames, getMissingRequiredInputs, getName, getNumParameters, getOutInoutNames, getOutNames, getParameter, getParameterDescriptor, getParameterDescriptorUnconditioned, getParameterNames, getParameterUnconditioned, getSupplementalNames, getVerbose, getVersion, handleOperatorExecutionProgressEvent, hasInOutParameters, hasParameter, isAnnotatedParameter, isConfigured, print, print, print, printInterface, printInterface, readHistory, reinitializeParameterDescriptors, removeOperatorExecutionProgressEventListener, removeParameter, runOp, runOp, runOp, setConstructionMode, setConstructionMode, setConstructionMode, setHidingMode, setName, setParameter, setParameterUnconditioned, setVerbose, toStringVerbose, unconfiguredItems, validate, validateCustom, validateGeneric, writeHistory, writeHistory, writeHistory

Methods inherited from class java.lang.Object

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

Field Detail

inputImage

@Parameter(label="Binary Input Image",
           required=true,
           direction=IN,
           description="Binary input image.",
           mode=STANDARD,
           dataIOOrder=0)
private transient MTBImageByte inputImage

Binary input image.

distanceMetric

@Parameter(label="Distance Metric",
           required=true,
           direction=IN,
           description="Used distance metric",
           mode=STANDARD,
           dataIOOrder=1)
private DistanceTransform.DistanceMetric distanceMetric

Distance metric to apply.

foreground

@Parameter(label="Foreground Color",
           required=true,
           direction=IN,
           description="Color of foreground.",
           mode=STANDARD,
           dataIOOrder=2)
private DistanceTransform.ForegroundColor foreground

Foreground color of the foreground object.

extractPrecursorInfos

@Parameter(label="Extract Precursor Iinformation?",
           required=true,
           direction=IN,
           description="Flag for precursor infos.",
           mode=STANDARD,
           dataIOOrder=3)
private boolean extractPrecursorInfos

Flag to enable/disable extraction of precursor infos.

distanceImg

@Parameter(label="Distance Map Image",
           direction=OUT,
           description="Image of the distance map.")
private transient MTBImage distanceImg

The distance field as MTBImage.

distanceMap

@Parameter(label="Distance Map",
           direction=OUT,
           description="2D distance map array.")
private double[][] distanceMap

The distance field as two-dimensional double array. Organized as double[y-dimension][x-dimension].

precursorMap

@Parameter(label="Precursor Map",
           direction=OUT,
           description="2D map of precursor pixels for each position.")
private Point2D.Double[][] precursorMap

Map of precursor positions for each pixel in the background.

closestObjectPixelMap

@Parameter(label="Closest Object Pixel Map",
           direction=OUT,
           description="Map of closest object pixels for each position.")
private Point2D.Double[][] closestObjectPixelMap

Map of closest object pixels for each background location.

width

private int width

Width of the given image.

height

private int height

Height of the given image.

Constructor Detail

DistanceTransform

public DistanceTransform()
                  throws de.unihalle.informatik.Alida.exceptions.ALDOperatorException

Standard constructor.

Throws:

de.unihalle.informatik.Alida.exceptions.ALDOperatorException - Thrown in case of failure.

DistanceTransform

public DistanceTransform(MTBImageByte image,
                         DistanceTransform.DistanceMetric dm,
                         DistanceTransform.ForegroundColor fg)
                  throws de.unihalle.informatik.Alida.exceptions.ALDOperatorException

Constructor to create a new DistanceTransform object.

Parameters:

image - the input image to calculate the distance map on it

dm - the distance metric

fg - set foreground white or black

Throws:

de.unihalle.informatik.Alida.exceptions.ALDOperatorException - Thrown in case of failure.

Method Detail

getInImg

public MTBImageByte getInImg()

Get the input image.

Returns:

Input image.

setInImg

public void setInImg(MTBImageByte inImg)

Set the input image.

Parameters:

inImg - Input image.

getDistMetric

public DistanceTransform.DistanceMetric getDistMetric()

Get the used distance metric.

Returns:

Distance metric.

setDistMetric

public void setDistMetric(DistanceTransform.DistanceMetric metric)

Set the distance metric.

Parameters:

metric - Distance metric to apply.

getForeground

public DistanceTransform.ForegroundColor getForeground()

Get the used foreground color.

Returns:

Foreground color.

setForeground

public void setForeground(DistanceTransform.ForegroundColor fColor)

Set the foreground color.

Parameters:

fColor - Foreground color.

setPrecursorInfosEnabled

public void setPrecursorInfosEnabled(boolean f)

Enable or disable extraction of additional precursor infos.

Parameters:

f - If true, additional infos are extracted.

getDistanceImage

public MTBImage getDistanceImage()

Get the calculated distance map image.

Returns:

Distance map image.

getDistanceMap

public double[][] getDistanceMap()

Get the calculated distance map.

First dimension specifies the y-coordinate of the field, and the second dimension specifies the x-coordinate.

Returns:

Distance map.

getPrecursorMap

public Point2D.Double[][] getPrecursorMap()

Get the calculated precursor map.

First dimension specifies the y-coordinate of the field, and the second dimension specifies the x-coordinate.

Returns:

Precursor map.

getClosestObjectPixelMap

public Point2D.Double[][] getClosestObjectPixelMap()

Get the calculated map of closest object pixels.

First dimension specifies the y-coordinate of the field, and the second dimension specifies the x-coordinate.

Returns:

Closest object pixel map.

getWidth

public int getWidth()

Get image width.

Returns:

Width of the input image.

getHeight

public int getHeight()

Get image height.

Returns:

Height of the input image.

operate

protected void operate()

Specified by:

operate in class de.unihalle.informatik.Alida.operator.ALDOperator

calcDM

private void calcDM()

Method to calculate the distance map of the given binary image using the Chamfer-algorithm.

A specified distance metric and the fore- and background of the binary image can be chosen. A neighborhood of 8 is used for the distance calculations.