java.awt.image
Class LookupTable

java.lang.Object
  java.awt.image.LookupTable

Direct Known Subclasses:

ByteLookupTable, ShortLookupTable

public abstract class LookupTable

extends Object

This abstract class defines a lookup table object. ByteLookupTable and ShortLookupTable are subclasses, which contain byte and short data, respectively. A lookup table contains data arrays for one or more bands (or components) of an image (for example, separate arrays for R, G, and B), and it contains an offset which will be subtracted from the input values before indexing into the arrays. This allows an array smaller than the native data size to be provided for a constrained input. If there is only one array in the lookup table, it will be applied to all bands. All arrays must be the same size.

See Also:

ByteLookupTable, ShortLookupTable, LookupOp

Field Summary

(package private) int	numComponents Constants
(package private) int	numEntries
(package private) int	offset

Constructor Summary

protected

LookupTable(int offset, int numComponents) Constructs a new LookupTable from the number of components and an offset into the lookup table.

Method Summary

int	getNumComponents() Returns the number of components in the lookup table.
int	getOffset() Returns the offset.
abstract int[]	lookupPixel(int[] src, int[] dest) Returns an int array of components for one pixel.

Methods inherited from class java.lang.Object

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

Field Detail

numComponents

int numComponents

Constants

offset

int offset

numEntries

int numEntries

Constructor Detail

LookupTable

protected LookupTable(int offset,
                      int numComponents)

Constructs a new LookupTable from the number of components and an offset into the lookup table.

Parameters:

offset - the offset to subtract from input values before indexing into the data arrays for this LookupTable

numComponents - the number of data arrays in this LookupTable

Throws:

IllegalArgumentException - if offset is less than 0 or if numComponents is less than 1

Method Detail

getNumComponents

public int getNumComponents()

Returns the number of components in the lookup table.

Returns:

the number of components in this LookupTable.

getOffset

public int getOffset()

Returns the offset.

Returns:

the offset of this LookupTable.

lookupPixel

public abstract int[] lookupPixel(int[] src,
                                  int[] dest)

Returns an int array of components for one pixel. The dest array contains the result of the lookup and is returned. If dest is null, a new array is allocated. The source and destination can be equal.

Parameters:

src - the source array of components of one pixel

dest - the destination array of components for one pixel, translated with this LookupTable

Returns:

an int array of components for one pixel.