org.geotools.geometry

Class PixelTranslation

Object

PixelTranslation

All Implemented Interfaces:

Serializable

public final class PixelTranslation
extends Object
implements Serializable

The translation to apply for different values of PixelOrientation.

Since:

2.5

Author:

Martin Desruisseaux (IRD)

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
double	dx The translation among the x axis relative to pixel center.
double	dy The translation among the y axis relative to pixel center.
PixelOrientation	orientation The pixel orientation for this translation.

Method Summary

Modifier and Type	Method and Description
static PixelOrientation	getPixelOrientation(double dx, double dy) Returns the pixel orientation for the given offset, or null if none.
static PixelOrientation	getPixelOrientation(PixelInCell anchor) Returns the pixel orientation for the given PixelInCell code.
static double	getPixelTranslation(PixelInCell anchor) Returns the position relative to the pixel center.
static PixelTranslation	getPixelTranslation(PixelOrientation anchor) Returns the specified position relative to the pixel center.
String	toString() Returns a string representation of this pixel translation.
static MathTransform	translate(MathTransform gridToCRS, PixelInCell current, PixelInCell expected) Translates the specified math transform according the specified pixel orientations.
static MathTransform	translate(MathTransform gridToCRS, PixelOrientation current, PixelOrientation expected, int xDimension, int yDimension) Translates the specified math transform according the specified pixel orientations.

Methods inherited from class Object

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

Field Detail

orientation

public final PixelOrientation orientation

The pixel orientation for this translation.

dx

public final double dx

The translation among the x axis relative to pixel center. The value is typically in the [-0.5 .. +0.5] range.

dy

public final double dy

The translation among the y axis relative to pixel center. The value is typically in the [-0.5 .. +0.5] range.

Method Detail

getPixelOrientation

public static PixelOrientation getPixelOrientation(PixelInCell anchor)
                                            throws IllegalArgumentException

Returns the pixel orientation for the given PixelInCell code.

Parameters:

anchor - The PixelInCell code, or null.

Returns:

The corresponding pixel orientation, or null if the argument was null.

Throws:

IllegalArgumentException - if the given code is unknown.

getPixelTranslation

public static double getPixelTranslation(PixelInCell anchor)

Returns the position relative to the pixel center. This method returns a value from the following table:

Pixel in cell	offset
CELL_CENTER	0.0
CELL_CORNER	-0.5

This method is typically used for n-dimensional grids, where the number of dimension is unknown.

Parameters:

anchor - The "pixel in cell" value.

Returns:

The translation for the given "pixel in cell" value.

getPixelTranslation

public static PixelTranslation getPixelTranslation(PixelOrientation anchor)
                                            throws IllegalArgumentException

Returns the specified position relative to the pixel center. This method returns a value from the following table:

Pixel orientation	x	y
CENTER	0.0	0.0
UPPER_LEFT	-0.5	-0.5
UPPER_RIGHT	+0.5	-0.5
LOWER_LEFT	-0.5	+0.5
LOWER_RIGHT	+0.5	+0.5

This method can be used for grid restricted to 2 dimensions.

Parameters:

anchor - The pixel orientation.

Returns:

The position relative to the pixel center.

Throws:

IllegalArgumentException - if the specified orientation is unknown.

getPixelOrientation

public static PixelOrientation getPixelOrientation(double dx,
                                                   double dy)

Returns the pixel orientation for the given offset, or null if none. This is the reverse of getPixelTranslation(PixelOrientation).

Parameters:

dx - The translation along x axis.

dy - The translation along y axis.

Returns:

The pixel orientation of the given values, or null if none.

translate

public static MathTransform translate(MathTransform gridToCRS,
                                      PixelInCell current,
                                      PixelInCell expected)

Translates the specified math transform according the specified pixel orientations.

Parameters:

gridToCRS - A math transform from pixel coordinates to any CRS.

current - The pixel orientation of the given gridToCRS transform.

expected - The pixel orientation of the desired transform.

Returns:

The translation from current to expected.

translate

public static MathTransform translate(MathTransform gridToCRS,
                                      PixelOrientation current,
                                      PixelOrientation expected,
                                      int xDimension,
                                      int yDimension)

Translates the specified math transform according the specified pixel orientations.

Parameters:

gridToCRS - A math transform from pixel coordinates to any CRS.

current - The pixel orientation of the given gridToCRS transform.

expected - The pixel orientation of the desired transform.

xDimension - The dimension of x coordinates (pixel columns). Often 0.

yDimension - The dimension of y coordinates (pixel rows). Often 1.

Returns:

The translation from current to expected.

toString

public String toString()

Returns a string representation of this pixel translation.

Overrides:

toString in class Object