net.sourceforge.jiu.data

Class Palette

Implemented Interfaces:
RGBIndex

public class Palette
extends java.lang.Object
implements RGBIndex

This class represents a palette, a list of RGB colors. An RGB color here has three int values for its red, green and blue intensity. Each intensity value must be larger than or equal to zero and smaller than or equal to the maximum intensity value that can be given to the constructor Palette(int,int). This maximum value is typically 255. Note that the number of entries in a palette is restricted only by the element index type int so that palettes with more than 256 entries are no problem. When accessing (reading or writing) samples of this palette, use the constants RGBIndex.INDEX_RED, RGBIndex.INDEX_GREEN and RGBIndex.INDEX_BLUE of this class to define a color channel.
Author:
Marco Schmidt
See Also:
PalettedImage

Field Summary

private int[][]
data
private int
maxValue
private int
numEntries

Fields inherited from interface net.sourceforge.jiu.data.RGBIndex

INDEX_BLUE, INDEX_GREEN, INDEX_RED

Constructor Summary

Palette(int numEntries)
Create a palette with the given number of entries and a maximum value of 255.
Palette(int numEntries, int maxValue)
Create a palette with the given number of entries and a maximum value for each sample.

Method Summary

Object
clone()
Creates a copy of this palette, allocating a new Palette object and copying each RGB triplet to the new palette.
long
getAllocatedMemory()
Returns the amount of memory in bytes allocated for this palette.
int
getMaxValue()
Returns the maximum value allowed for a sample.
int
getNumEntries()
Returns the number of entries in this palette.
int
getSample(int channelIndex, int entryIndex)
Returns one of the samples of this palette.
int[]
getSamples(int channelIndex)
Returns all samples of one channel as an int array.
boolean
isBlackAndWhite()
Checks if all entries of this palette are either black or white.
boolean
isGray()
Checks if this palette is gray, i.e., checks if all entries are gray.
void
put(int entryIndex, int red, int green, int blue)
void
putSample(int channelIndex, int entryIndex, int newValue)
Sets one sample of one color entry in the palette to a new value.

Field Details

data

private int[][] data

maxValue

private int maxValue

numEntries

private int numEntries

Constructor Details

Palette

public Palette(int numEntries)
Create a palette with the given number of entries and a maximum value of 255.
Parameters:
numEntries - the number of entries to be accessible in this palette

Palette

public Palette(int numEntries,
               int maxValue)
Create a palette with the given number of entries and a maximum value for each sample.
Parameters:
numEntries - the number of entries to be accessible in this palette
maxValue - the maximum value to be allowed for each sample

Method Details

clone

public Object clone()
Creates a copy of this palette, allocating a new Palette object and copying each RGB triplet to the new palette. Then returns the new palette. Thus, a "deep" copy of this Palette object is created, not a "shallow" one.
Returns:
newly-created palette

getAllocatedMemory

public long getAllocatedMemory()
Returns the amount of memory in bytes allocated for this palette.

getMaxValue

public int getMaxValue()
Returns the maximum value allowed for a sample.
Returns:
the maximum sample value

getNumEntries

public int getNumEntries()
Returns the number of entries in this palette.
Returns:
the number of entries in this palette

getSample

public int getSample(int channelIndex,
                     int entryIndex)
Returns one of the samples of this palette.
Parameters:
channelIndex - one of the three channels; must be RGBIndex.INDEX_RED, RGBIndex.INDEX_GREEN or RGBIndex.INDEX_BLUE
entryIndex - the index of the color to be addressed, must be from 0 to getNumEntries() - 1
Returns:
the requested sample

getSamples

public int[] getSamples(int channelIndex)
Returns all samples of one channel as an int array.
Returns:
array with samples

isBlackAndWhite

public boolean isBlackAndWhite()
Checks if all entries of this palette are either black or white. An entry is black if all three intensitites (red, green and blue) are 0, it is white if they are all equal to getMaxValue(). No particular order of entries (e.g. first color black, second white) is demanded and no specific number of entries (e.g. 2). This means that a palette is black and white if it contains ten entries that are all black.
Returns:
if the palette contains only the colors black and white

isGray

public boolean isGray()
Checks if this palette is gray, i.e., checks if all entries are gray. This is the case if for all entries red, green and blue have the same intensity.
Returns:
if the palette contains only shades of gray

put

public void put(int entryIndex,
                int red,
                int green,
                int blue)

putSample

public void putSample(int channelIndex,
                      int entryIndex,
                      int newValue)
Sets one sample of one color entry in the palette to a new value.
Parameters:
channelIndex -