java.awt.image
Class Raster

java.lang.Object   
  java.awt.image.Raster

Direct Known Subclasses:

WritableRaster

public class Raster
extends Object   

A class representing a rectangular array of pixels. A Raster encapsulates a DataBuffer that stores the sample values and a SampleModel that describes how to locate a given sample value in a DataBuffer.

A Raster defines values for pixels occupying a particular rectangular area of the plane, not necessarily including (0, 0). The rectangle, known as the Raster's bounding rectangle and available by means of the getBounds method, is defined by minX, minY, width, and height values. The minX and minY values define the coordinate of the upper left corner of the Raster. References to pixels outside of the bounding rectangle may result in an exception being thrown, or may result in references to unintended elements of the Raster's associated DataBuffer. It is the user's responsibility to avoid accessing such pixels.

A SampleModel describes how samples of a Raster are stored in the primitive array elements of a DataBuffer. Samples may be stored one per data element, as in a PixelInterleavedSampleModel or BandedSampleModel, or packed several to an element, as in a SinglePixelPackedSampleModel or MultiPixelPackedSampleModel. The SampleModel is also controls whether samples are sign extended, allowing unsigned data to be stored in signed Java data types such as byte, short, and int.

Although a Raster may live anywhere in the plane, a SampleModel makes use of a simple coordinate system that starts at (0, 0). A Raster therefore contains a translation factor that allows pixel locations to be mapped between the Raster's coordinate system and that of the SampleModel. The translation from the SampleModel coordinate system to that of the Raster may be obtained by the getSampleModelTranslateX and getSampleModelTranslateY methods.

A Raster may share a DataBuffer with another Raster either by explicit construction or by the use of the createChild and createTranslatedChild methods. Rasters created by these methods can return a reference to the Raster they were created from by means of the getParent method. For a Raster that was not constructed by means of a call to createTranslatedChild or createChild, getParent will return null.

The createTranslatedChild method returns a new Raster that shares all of the data of the current Raster, but occupies a bounding rectangle of the same width and height but with a different starting point. For example, if the parent Raster occupied the region (10, 10) to (100, 100), and the translated Raster was defined to start at (50, 50), then pixel (20, 20) of the parent and pixel (60, 60) of the child occupy the same location in the DataBuffer shared by the two Rasters. In the first case, (-10, -10) should be added to a pixel coordinate to obtain the corresponding SampleModel coordinate, and in the second case (-50, -50) should be added.

The translation between a parent and child Raster may be determined by subtracting the child's sampleModelTranslateX and sampleModelTranslateY values from those of the parent.

The createChild method may be used to create a new Raster occupying only a subset of its parent's bounding rectangle (with the same or a translated coordinate system) or with a subset of the bands of its parent.

All constructors are protected. The correct way to create a Raster is to use one of the static create methods defined in this class. These methods create instances of Raster that use the standard Interleaved, Banded, and Packed SampleModels and that may be processed more efficiently than a Raster created by combining an externally generated SampleModel and DataBuffer.

See Also:

DataBuffer , SampleModel , PixelInterleavedSampleModel , BandedSampleModel , SinglePixelPackedSampleModel , MultiPixelPackedSampleModel

Field Summary

protected DataBuffer	dataBuffer The DataBuffer that stores the image data.
protected int	height The height of this Raster.
protected int	minX The X coordinate of the upper-left pixel of this Raster.
protected int	minY The Y coordinate of the upper-left pixel of this Raster.
protected int	numBands The number of bands in the Raster.
protected int	numDataElements The number of DataBuffer data elements per pixel.
protected Raster	parent The parent of this Raster, or null.
protected SampleModel	sampleModel The SampleModel that describes how pixels from this Raster are stored in the DataBuffer.
protected int	sampleModelTranslateX The X translation from the coordinate space of the Raster's SampleModel to that of the Raster.
protected int	sampleModelTranslateY The Y translation from the coordinate space of the Raster's SampleModel to that of the Raster.
protected int	width The width of this Raster.

Constructor Summary

protected	Raster (SampleModel sampleModel, DataBuffer dataBuffer, Point origin) Constructs a Raster with the given SampleModel and DataBuffer.
protected	Raster (SampleModel sampleModel, DataBuffer dataBuffer, Rectangle aRegion, Point sampleModelTranslate, Raster parent) Constructs a Raster with the given SampleModel, DataBuffer, and parent.
protected	Raster (SampleModel sampleModel, Point origin) Constructs a Raster with the given SampleModel.

Method Summary

static WritableRaster	createBandedRaster (DataBuffer dataBuffer, int w, int h, int scanlineStride, int[] bankIndices, int[] bandOffsets, Point location) Creates a Raster based on a BandedSampleModel with the specified DataBuffer, width, height, scanline stride, bank indices, and band offsets.
static WritableRaster	createBandedRaster (int dataType, int w, int h, int scanlineStride, int[] bankIndices, int[] bandOffsets, Point location) Creates a Raster based on a BandedSampleModel with the specified data type, width, height, scanline stride, bank indices and band offsets.
static WritableRaster	createBandedRaster (int dataType, int w, int h, int bands, Point location) Creates a Raster based on a BandedSampleModel with the specified data type, width, height, and number of bands.
Raster	createChild (int parentX, int parentY, int width, int height, int childMinX, int childMinY, int[] bandList) Returns a new Raster which shares all or part of this Raster's DataBuffer.
WritableRaster	createCompatibleWritableRaster () Create a compatible WritableRaster the same size as this Raster with the same SampleModel and a new initialized DataBuffer.
WritableRaster	createCompatibleWritableRaster (int w, int h) Create a compatible WritableRaster with the specified size, a new SampleModel, and a new initialized DataBuffer.
WritableRaster	createCompatibleWritableRaster (int x, int y, int w, int h) Create a compatible WritableRaster with the specified location (minX, minY) and size (width, height), a new SampleModel, and a new initialized DataBuffer.
WritableRaster	createCompatibleWritableRaster (Rectangle rect) Create a compatible WritableRaster with location (minX, minY) and size (width, height) specified by rect, a new SampleModel, and a new initialized DataBuffer.
static WritableRaster	createInterleavedRaster (DataBuffer dataBuffer, int w, int h, int scanlineStride, int pixelStride, int[] bandOffsets, Point location) Creates a Raster based on a PixelInterleavedSampleModel with the specified DataBuffer, width, height, scanline stride, pixel stride, and band offsets.
static WritableRaster	createInterleavedRaster (int dataType, int w, int h, int scanlineStride, int pixelStride, int[] bandOffsets, Point location) Creates a Raster based on a PixelInterleavedSampleModel with the specified data type, width, height, scanline stride, pixel stride, and band offsets.
static WritableRaster	createInterleavedRaster (int dataType, int w, int h, int bands, Point location) Creates a Raster based on a PixelInterleavedSampleModel with the specified data type, width, height, and number of bands.
static WritableRaster	createPackedRaster (DataBuffer dataBuffer, int w, int h, int scanlineStride, int[] bandMasks, Point location) Creates a Raster based on a SinglePixelPackedSampleModel with the specified DataBuffer, width, height, scanline stride, and band masks.
static WritableRaster	createPackedRaster (DataBuffer dataBuffer, int w, int h, int bitsPerPixel, Point location) Creates a Raster based on a MultiPixelPackedSampleModel with the specified DataBuffer, width, height, and bits per pixel.
static WritableRaster	createPackedRaster (int dataType, int w, int h, int[] bandMasks, Point location) Creates a Raster based on a SinglePixelPackedSampleModel with the specified data type, width, height, and band masks.
static WritableRaster	createPackedRaster (int dataType, int w, int h, int bands, int bitsPerBand, Point location) Creates a Raster based on a packed SampleModel with the specified data type, width, height, number of bands, and bits per band.
static Raster	createRaster (SampleModel sm, DataBuffer db, Point location) Creates a Raster with the specified SampleModel and DataBuffer.
Raster	createTranslatedChild (int childMinX, int childMinY) Create a Raster with the same size, SampleModel and DataBuffer as this one, but with a different location.
static WritableRaster	createWritableRaster (SampleModel sm, DataBuffer db, Point location) Creates a WritableRaster with the specified SampleModel and DataBuffer.
static WritableRaster	createWritableRaster (SampleModel sm, Point location) Creates a WritableRaster with the specified SampleModel.
Rectangle	getBounds () Returns the bounding Rectangle of this Raster.
DataBuffer	getDataBuffer () Returns the DataBuffer associated with this Raster.
Object	getDataElements (int x, int y, int w, int h, Object outData) Returns the pixel data for the specified rectangle of pixels in a primitive array of type TransferType.
Object	getDataElements (int x, int y, Object outData) Returns data for a single pixel in a primitive array of type TransferType.
int	getHeight () Returns the height in pixels of the Raster.
int	getMinX () Returns the minimum valid X coordinate of the Raster.
int	getMinY () Returns the minimum valid Y coordinate of the Raster.
int	getNumBands () Returns the number of bands (samples per pixel) in this Raster.
int	getNumDataElements () Returns the number of data elements needed to transfer one pixel via the getDataElements and setDataElements methods.
Raster	getParent () Returns the parent Raster (if any) of this Raster or null.
double[]	getPixel (int x, int y, double[] dArray) Returns the samples in an array of double for the specified pixel.
float[]	getPixel (int x, int y, float[] fArray) Returns the samples in an array of float for the specified pixel.
int[]	getPixel (int x, int y, int[] iArray) Returns the samples in an array of int for the specified pixel.
double[]	getPixels (int x, int y, int w, int h, double[] dArray) Returns a double array containing all samples for a rectangle of pixels, one sample per array element.
float[]	getPixels (int x, int y, int w, int h, float[] fArray) Returns a float array containing all samples for a rectangle of pixels, one sample per array element.
int[]	getPixels (int x, int y, int w, int h, int[] iArray) Returns an int array containing all samples for a rectangle of pixels, one sample per array element.
int	getSample (int x, int y, int b) Returns the sample in a specified band for the pixel located at (x,y) as an int.
double	getSampleDouble (int x, int y, int b) Returns the sample in a specified band for a pixel located at (x,y) as a double.
float	getSampleFloat (int x, int y, int b) Returns the sample in a specified band for the pixel located at (x,y) as a float.
SampleModel	getSampleModel () Returns the SampleModel that describes the layout of the image data.
int	getSampleModelTranslateX () Returns the X translation from the coordinate system of the SampleModel to that of the Raster.
int	getSampleModelTranslateY () Returns the Y translation from the coordinate system of the SampleModel to that of the Raster.
double[]	getSamples (int x, int y, int w, int h, int b, double[] dArray) Returns the samples for a specified band for a specified rectangle of pixels in a double array, one sample per array element.
float[]	getSamples (int x, int y, int w, int h, int b, float[] fArray) Returns the samples for a specified band for the specified rectangle of pixels in a float array, one sample per array element.
int[]	getSamples (int x, int y, int w, int h, int b, int[] iArray) Returns the samples for a specified band for the specified rectangle of pixels in an int array, one sample per array element.
int	getTransferType () Returns the TransferType used to transfer pixels via the getDataElements and setDataElements methods.
int	getWidth () Returns the width in pixels of the Raster.

Methods inherited from class java.lang.Object

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