jaitools.media.jai.kernel
Class KernelFactory

java.lang.Object
  jaitools.media.jai.kernel.KernelFactory

public class KernelFactory
extends Object

A factory class with static methods to create a variety of KernelJAI objects with specified geometries

Since:

1.0

Version:

$Id: KernelFactory.java 1383 2011-02-10 11:22:29Z michael.bedward $

Author:

Michael Bedward

Nested Class Summary

static class

KernelFactory.ValueType Meaning of the kernel values

Constructor Summary

KernelFactory()

Method Summary

static javax.media.jai.KernelJAI	createAnnulus(int outerRadius, int innerRadius, KernelFactory.ValueType type, float centreValue) Creates a new KernelJAI object with an annular configuration (like a doughnut).
static javax.media.jai.KernelJAI	createCircle(int radius) Create a new KernelJAI object with a circular configuration.
static javax.media.jai.KernelJAI	createCircle(int radius, KernelFactory.ValueType type, float centreValue) Creates a new KernelJAI object with a circular configuration.
static javax.media.jai.KernelJAI	createFromShape(Shape shape, AffineTransform transform, KernelFactory.ValueType type, int keyX, int keyY, float keyValue) Create a new KernelJAI object by rasterizing a shape.
static javax.media.jai.KernelJAI	createRectangle(int width, int height) Creates a new KernelJAI object with a rectangular configuraton.
static javax.media.jai.KernelJAI	createRectangle(int width, int height, KernelFactory.ValueType type, int keyX, int keyY, float keyValue) Creates a new KernelJAI object with a rectangular configuration.

Methods inherited from class java.lang.Object

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

Constructor Detail

KernelFactory

public KernelFactory()

Method Detail

createCircle

public static javax.media.jai.KernelJAI createCircle(int radius)

Create a new KernelJAI object with a circular configuration. Kernel elements within the circle will have value 1.0f; those outside will have value 0.0f.

This is equivalent to, but faster than, calling...

createCircle(radius, Kernel.ValueType.BINARY, 1.0f)

Parameters:

radius - radius of the circle

Returns:

a new instance of KernelJAI

createCircle

public static javax.media.jai.KernelJAI createCircle(int radius,
                                                     KernelFactory.ValueType type,
                                                     float centreValue)

Creates a new KernelJAI object with a circular configuration. The kernel width is 2*radius + 1. The kernel's key element is at position x=radius, y=radius

Parameters:

radius - the radius of the circle expressed in pixels

type - one of KernelFactory.ValueType.BINARY, KernelFactory.ValueType.DISTANCE or KernelFactory.ValueType.INVERSE_DISTANCE

centreValue - the value to assign to the kernel centre (key element)

Returns:

a new instance of KernelJAI

createAnnulus

public static javax.media.jai.KernelJAI createAnnulus(int outerRadius,
                                                      int innerRadius,
                                                      KernelFactory.ValueType type,
                                                      float centreValue)

Creates a new KernelJAI object with an annular configuration (like a doughnut). The kernel width is 2*outerRadius + 1. The kernel's key element is at position x=outerRadius, y=outerRadius

An IllegalArgumentException will be thrown if:

• The value of outerRadius not greater than 0
• The value of innerRadius is not less than outerRadius

Calling this method with innerRadius == 0 is equivalent to calling createCircle(int)

Parameters:

outerRadius - the radius of the circle expressed in pixels

innerRadius - the radius of the 'hole' of the annulus

type - one of KernelFactory.ValueType.BINARY, KernelFactory.ValueType.DISTANCE or KernelFactory.ValueType.INVERSE_DISTANCE

centreValue - the value to assign to the kernel centre (key element)

Returns:

a new instance of KernelJAI

createRectangle

public static javax.media.jai.KernelJAI createRectangle(int width,
                                                        int height)

Creates a new KernelJAI object with a rectangular configuraton. An IllegalArgumentException will be thrown if width or height are less than 1.

This is equivalent to calling...

createRectangle(width, height, Kernel.ValueType.BINARY, width/2, height/2, 1.0f)

Parameters:

width - rectangle width

height - rectangle height

Returns:

a new instance of KernelJAI

createRectangle

public static javax.media.jai.KernelJAI createRectangle(int width,
                                                        int height,
                                                        KernelFactory.ValueType type,
                                                        int keyX,
                                                        int keyY,
                                                        float keyValue)

Creates a new KernelJAI object with a rectangular configuration.

An IllegalArgumentException will be thrown if:

• width or height are less than 1
• keyX is not in the range 0:width-1
• keyY is not in the range 0:height-1

Parameters:

width - rectangle width

height - rectangle height

type - one of KernelFactory.ValueType.BINARY, KernelFactory.ValueType.DISTANCE or KernelFactory.ValueType.INVERSE_DISTANCE

keyX - x position of the key element

keyY - y position of the key element (y coords increase downwards)

keyValue - value of the key element

Returns:

a new instance of KernelJAI

createFromShape

public static javax.media.jai.KernelJAI createFromShape(Shape shape,
                                                        AffineTransform transform,
                                                        KernelFactory.ValueType type,
                                                        int keyX,
                                                        int keyY,
                                                        float keyValue)

Create a new KernelJAI object by rasterizing a shape. The shape must be a closed polygon. The rasterizing process checks whether the centre of each pixel is inside the polygon.

This method can cope with arbitrary shape bounds, ie. there is no need to set the bounding rectangle to have origin x=0, y=0. The values of keyX and keyY, which specify the position of the kernel's key element, must be within the bounds of the shape as passed to this method, but do not need to be inside the shape itself.

Parameters:

shape - an object representing a closed polygon

transform - an optional AffineTransform to relate shape coordinates to kernel element coordinates. May be null. This is useful to scale and/or rotate the shape.

type - one of KernelFactory.ValueType.BINARY, KernelFactory.ValueType.DISTANCE or KernelFactory.ValueType.INVERSE_DISTANCE

keyX - the x coord of the key element

keyY - the y coord of the key element

keyValue - the value of the key element

Returns:

a new instance of KernelJAI