com.pearsoneduc.ip.op
Class GreyStructElement

java.lang.Object
  |
  +--com.pearsoneduc.ip.op.StructElement
        |
        +--com.pearsoneduc.ip.op.GreyStructElement

public class GreyStructElement

extends StructElement

implements java.lang.Cloneable

A structuring element for the morphological processing of greyscale images.

Version:

1.0 [1999/08/31]

Author:

Nick Efford

Fields inherited from class com.pearsoneduc.ip.op.StructElement

height, origin, pixel, width

Constructor Summary

GreyStructElement(int value)
Creates a 3x3 square SE with pixels set to the specified value.

GreyStructElement(int w, int h, int value)
Creates a rectangular GreyStructElement with the specified dimensions and pixel value.

GreyStructElement(int w, int h, java.awt.Point p, int value)
Creates an instance of a GreyStructElement with the specified dimensions, origin and pixel value.

GreyStructElement(java.io.Reader source)
Creates an instance of a GreyStructElement by reading data.

Method Summary

int	above(java.awt.image.Raster raster, int x, int y) Calculates the minimum distance that a rotated SE would need to be pushed up so as to be above the image.
int	below(java.awt.image.Raster raster, int x, int y) Calculates the maximum distance that the SE can be pushed up whilst remaining beneath an image.
java.lang.Object	clone()
boolean	equals(java.lang.Object obj) Tests for equality with another GreyStructElement.
GreyStructElement	getRotatedVersion()
void	setPixel(int x, int y, int value) Sets a pixel in the structuring element to the specified value.
void	setPixels(int value) Sets all pixels of the SE to the specified value.
void	setPixels(int[] value) Copies values from a one-dimensional array into the SE.
void	setPixels(int[][] value) Copies values from a two-dimensional array into the SE.
void	setPixels(java.lang.String valueString) Copies values from a String into the SE.
void	write(java.io.Writer destination) Writes SE data, including a header, to the specified destination.
void	writePixels(java.io.Writer destination) Writes SE pixel values to the specified destination.

Methods inherited from class com.pearsoneduc.ip.op.StructElement

getHeight, getOrigin, getPixel, getWidth, readInt, setOrigin, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

GreyStructElement

public GreyStructElement(int value)
                  throws StructElementException

Creates a 3x3 square SE with pixels set to the specified value.

Parameters:

value - SE pixel value

GreyStructElement

public GreyStructElement(int w,
                         int h,
                         int value)
                  throws StructElementException

Creates a rectangular GreyStructElement with the specified dimensions and pixel value.

Parameters:

w - desired SE width (greater than 0)

h - desired SE height (greater than 0)

value - SE pixel value

Throws:

StructElementException - if dimensions are invalid.

GreyStructElement

public GreyStructElement(int w,
                         int h,
                         java.awt.Point p,
                         int value)
                  throws StructElementException

Creates an instance of a GreyStructElement with the specified dimensions, origin and pixel value.

Parameters:

w - desired SE width (greater than 0)

h - desired SE height (greater than 0)

p - java.awt.Point object representing origin of SE

value - SE pixel value

Throws:

StructElementException - if dimensions are invalid.

GreyStructElement

public GreyStructElement(java.io.Reader source)
                  throws java.io.IOException,
                         StructElementException

Creates an instance of a GreyStructElement by reading data.

Parameters:

source - Reader representing source of SE data

Throws:

java.io.IOException - if there was an I/O error.

StructElementException - if the data do not conform to the required format or the dimensions, origin or SE values are not valid.

Method Detail

clone

public java.lang.Object clone()

Returns:

a copy of this GreyStructElement.

Overrides:

clone in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Tests for equality with another GreyStructElement.

Parameters:

obj - a GreyStructElement object

Returns:

true if the SEs are equal, false otherwise.

Overrides:

equals in class StructElement

setPixel

public void setPixel(int x,
                     int y,
                     int value)

Sets a pixel in the structuring element to the specified value.

Parameters:

x - x coordinate of SE pixel

y - y coordinate of SE pixel

value - new value for SE pixel

setPixels

public void setPixels(int value)

Sets all pixels of the SE to the specified value.

Parameters:

value - new value for SE pixels

setPixels

public void setPixels(int[] value)
               throws StructElementException

Copies values from a one-dimensional array into the SE.

Parameters:

value - array of values to be copied into the SE

Overrides:

setPixels in class StructElement

setPixels

public void setPixels(int[][] value)
               throws StructElementException

Copies values from a two-dimensional array into the SE.

Parameters:

value - array of values to be copied into SE

Overrides:

setPixels in class StructElement

setPixels

public void setPixels(java.lang.String valueString)
               throws StructElementException

Copies values from a String into the SE.

Parameters:

valueString - String of values to be copied into SE

Throws:

StructElementException - if string does not contain enough values.

Overrides:

setPixels in class StructElement

writePixels

public void writePixels(java.io.Writer destination)

Writes SE pixel values to the specified destination.

Parameters:

destination - Writer acting as destination for the SE data

Overrides:

writePixels in class StructElement

write

public void write(java.io.Writer destination)
           throws java.io.IOException

Writes SE data, including a header, to the specified destination.

Parameters:

destination - Writer acting as a destination for the SE

Throws:

java.io.IOException - if there was some kind of error when writing the header.

Overrides:

write in class StructElement

below

public int below(java.awt.image.Raster raster,
                 int x,
                 int y)

Calculates the maximum distance that the SE can be pushed up whilst remaining beneath an image. This is equivalent to the minimum distance between image pixel values and SE pixel values over the domain of the SE.

Note: this method does not check whether SE pixels lie beyond the bounds of the image!

Parameters:

raster - Raster of the image on which the SE will operate

x - x coordinate of pixel where SE will be placed

y - y coordinate of pixel where SE will be placed

Returns:

maximum distance that the SE can be pushed up.

above

public int above(java.awt.image.Raster raster,
                 int x,
                 int y)

Calculates the minimum distance that a rotated SE would need to be pushed up so as to be above the image.

Note: this method does not check whether SE pixels lie beyond the bounds of the image!

Parameters:

raster - Raster of the image on which the SE will operate

x - x coordinate of pixel where SE will be placed

y - y coordinate of pixel where SE will be placed

Returns:

minimum 'push-up' distance.

getRotatedVersion

public GreyStructElement getRotatedVersion()

Returns:

a version of this GreyStructElement that has been rotated through 180 degrees.