java.awt.image
Class SinglePixelPackedSampleModel

java.lang.Object
  java.awt.image.SampleModel
      java.awt.image.SinglePixelPackedSampleModel

public class SinglePixelPackedSampleModel

extends SampleModel

This class represents pixel data packed such that the N samples which make up a single pixel are stored in a single data array element, and each data data array element holds samples for only one pixel. This class supports TYPE_BYTE, TYPE_USHORT, TYPE_INT data types. All data array elements reside in the first bank of a DataBuffer. Accessor methods are provided so that the image data can be manipulated directly. Scanline stride is the number of data array elements between a given sample and the corresponding sample in the same column of the next scanline. Bit masks are the masks required to extract the samples representing the bands of the pixel. Bit offsets are the offsets in bits into the data array element of the samples representing the bands of the pixel.

The following code illustrates extracting the bits of the sample representing band b for pixel x,y from DataBuffer data:

      int sample = data.getElem(y * scanlineStride + x);
      sample = (sample & bitMasks[b]) >>> bitOffsets[b];
 

Field Summary

private int[]	bitMasks Bit masks for all bands of the image data.
private int[]	bitOffsets Bit Offsets for all bands of the image data.
private int[]	bitSizes Bit sizes for all the bands of the image data.
private int	maxBitSize Maximum bit size.
private int	scanlineStride Line stride of the region of image data described by this SinglePixelPackedSampleModel.

Fields inherited from class java.awt.image.SampleModel

dataType, height, numBands, width

Constructor Summary

SinglePixelPackedSampleModel(int dataType, int w, int h, int[] bitMasks)
Constructs a SinglePixelPackedSampleModel with bitMasks.length bands.

SinglePixelPackedSampleModel(int dataType, int w, int h, int scanlineStride, int[] bitMasks)
Constructs a SinglePixelPackedSampleModel with bitMasks.length bands and a scanline stride equal to scanlineStride data array elements.

Method Summary

SampleModel	createCompatibleSampleModel(int w, int h) Creates a new SinglePixelPackedSampleModel with the specified width and height.
DataBuffer	createDataBuffer() Creates a DataBuffer that corresponds to this SinglePixelPackedSampleModel.
SampleModel	createSubsetSampleModel(int[] bands) This creates a new SinglePixelPackedSampleModel with a subset of the bands of this SinglePixelPackedSampleModel.
boolean	equals(Object o) Indicates whether some other object is "equal to" this one.
int[]	getBitMasks() Returns the bit masks for all bands.
int[]	getBitOffsets() Returns the bit offsets into the data array element representing a pixel for all bands.
private long	getBufferSize() Returns the size of the buffer (in data array elements) needed for a data buffer that matches this SinglePixelPackedSampleModel.
Object	getDataElements(int x, int y, Object obj, DataBuffer data) Returns data for a single pixel in a primitive array of type TransferType.
int	getNumDataElements() Returns the number of data elements needed to transfer one pixel via the getDataElements and setDataElements methods.
int	getOffset(int x, int y) Returns the offset (in data array elements) of pixel (x,y).
int[]	getPixel(int x, int y, int[] iArray, DataBuffer data) Returns all samples in for the specified pixel in an int array.
int[]	getPixels(int x, int y, int w, int h, int[] iArray, DataBuffer data) Returns all samples for the specified rectangle of pixels in an int array, one sample per array element.
int	getSample(int x, int y, int b, DataBuffer data) Returns as int the sample in a specified band for the pixel located at (x,y).
int[]	getSamples(int x, int y, int w, int h, int b, int[] iArray, DataBuffer data) Returns the samples for a specified band for the specified rectangle of pixels in an int array, one sample per array element.
int[]	getSampleSize() Returns the number of bits per sample for all bands.
int	getSampleSize(int band) Returns the number of bits per sample for the specified band.
int	getScanlineStride() Returns the scanline stride of this SinglePixelPackedSampleModel.
int	hashCode() Returns a hash code value for the object.
private static void	initIDs()
void	setDataElements(int x, int y, Object obj, DataBuffer data) Sets the data for a single pixel in the specified DataBuffer from a primitive array of type TransferType.
void	setPixel(int x, int y, int[] iArray, DataBuffer data) Sets a pixel in the DataBuffer using an int array of samples for input.
void	setPixels(int x, int y, int w, int h, int[] iArray, DataBuffer data) Sets all samples for a rectangle of pixels from an int array containing one sample per array element.
void	setSample(int x, int y, int b, int s, DataBuffer data) Sets a sample in the specified band for the pixel located at (x,y) in the DataBuffer using an int for input.
void	setSamples(int x, int y, int w, int h, int b, int[] iArray, DataBuffer data) Sets the samples in the specified band for the specified rectangle of pixels from an int array containing one sample per array element.

Methods inherited from class java.awt.image.SampleModel

getDataElements, getDataType, getHeight, getNumBands, getPixel, getPixel, getPixels, getPixels, getSampleDouble, getSampleFloat, getSamples, getSamples, getTransferType, getWidth, setDataElements, setPixel, setPixel, setPixels, setPixels, setSample, setSample, setSamples, setSamples

Methods inherited from class java.lang.Object

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

Field Detail

bitMasks

private int[] bitMasks

Bit masks for all bands of the image data.

bitOffsets

private int[] bitOffsets

Bit Offsets for all bands of the image data.

bitSizes

private int[] bitSizes

Bit sizes for all the bands of the image data.

maxBitSize

private int maxBitSize

Maximum bit size.

scanlineStride

private int scanlineStride

Line stride of the region of image data described by this SinglePixelPackedSampleModel.

Constructor Detail

SinglePixelPackedSampleModel

public SinglePixelPackedSampleModel(int dataType,
                                    int w,
                                    int h,
                                    int[] bitMasks)

Constructs a SinglePixelPackedSampleModel with bitMasks.length bands. Each sample is stored in a data array element in the position of its corresponding bit mask. Each bit mask must be contiguous and masks must not overlap.

Parameters:

dataType - The data type for storing samples.

w - The width (in pixels) of the region of the image data described.

h - The height (in pixels) of the region of the image data described.

bitMasks - The bit masks for all bands.

Throws:

IllegalArgumentException - if dataType is not either DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT, or DataBuffer.TYPE_INT

SinglePixelPackedSampleModel

public SinglePixelPackedSampleModel(int dataType,
                                    int w,
                                    int h,
                                    int scanlineStride,
                                    int[] bitMasks)

Constructs a SinglePixelPackedSampleModel with bitMasks.length bands and a scanline stride equal to scanlineStride data array elements. Each sample is stored in a data array element in the position of its corresponding bit mask. Each bit mask must be contiguous and masks must not overlap.

Parameters:

dataType - The data type for storing samples.

w - The width (in pixels) of the region of image data described.

h - The height (in pixels) of the region of image data described.

scanlineStride - The line stride of the image data.

bitMasks - The bit masks for all bands.

Throws:

IllegalArgumentException - if w or h is not greater than 0

IllegalArgumentException - if any mask in bitMask is not contiguous

IllegalArgumentException - if dataType is not either DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT, or DataBuffer.TYPE_INT

Method Detail

initIDs

private static void initIDs()

getNumDataElements

public int getNumDataElements()

Returns the number of data elements needed to transfer one pixel via the getDataElements and setDataElements methods. For a SinglePixelPackedSampleModel, this is one.

Specified by:

getNumDataElements in class SampleModel

Returns:

the number of data elements.

See Also:

SampleModel.getDataElements(int, int, Object, DataBuffer), SampleModel.getDataElements(int, int, int, int, Object, DataBuffer), SampleModel.setDataElements(int, int, Object, DataBuffer), SampleModel.setDataElements(int, int, int, int, Object, DataBuffer), SampleModel.getTransferType()

getBufferSize

private long getBufferSize()

Returns the size of the buffer (in data array elements) needed for a data buffer that matches this SinglePixelPackedSampleModel.

createCompatibleSampleModel

public SampleModel createCompatibleSampleModel(int w,
                                               int h)

Creates a new SinglePixelPackedSampleModel with the specified width and height. The new SinglePixelPackedSampleModel will have the same storage data type and bit masks as this SinglePixelPackedSampleModel.

Specified by:

createCompatibleSampleModel in class SampleModel

Parameters:

w - the width of the resulting SampleModel

h - the height of the resulting SampleModel

Returns:

a SinglePixelPackedSampleModel with the specified width and height.

Throws:

IllegalArgumentException - if w or h is not greater than 0

createDataBuffer

public DataBuffer createDataBuffer()

Creates a DataBuffer that corresponds to this SinglePixelPackedSampleModel. The DataBuffer's data type and size will be consistent with this SinglePixelPackedSampleModel. The DataBuffer will have a single bank.

Specified by:

createDataBuffer in class SampleModel

Returns:

a DataBuffer corresponding to this SampleModel.

getSampleSize

public int[] getSampleSize()

Returns the number of bits per sample for all bands.

Specified by:

getSampleSize in class SampleModel

Returns:

the size of samples for all bands.

getSampleSize

public int getSampleSize(int band)

Returns the number of bits per sample for the specified band.

Specified by:

getSampleSize in class SampleModel

Parameters:

band - the specified band

Returns:

the size of the samples of the specified band.

getOffset

public int getOffset(int x,
                     int y)

Returns the offset (in data array elements) of pixel (x,y). The data element containing pixel x,y can be retrieved from a DataBuffer data with a SinglePixelPackedSampleModel sppsm as:

        data.getElem(sppsm.getOffset(x, y));
 

Returns:

the offset of the specified pixel.

getBitOffsets

public int[] getBitOffsets()

Returns the bit offsets into the data array element representing a pixel for all bands.

Returns:

the bit offsets representing a pixel for all bands.

getBitMasks

public int[] getBitMasks()

Returns the bit masks for all bands.

Returns:

the bit masks for all bands.

getScanlineStride

public int getScanlineStride()

Returns the scanline stride of this SinglePixelPackedSampleModel.

Returns:

the scanline stride of this SinglePixelPackedSampleModel.

createSubsetSampleModel

public SampleModel createSubsetSampleModel(int[] bands)

This creates a new SinglePixelPackedSampleModel with a subset of the bands of this SinglePixelPackedSampleModel. The new SinglePixelPackedSampleModel can be used with any DataBuffer that the existing SinglePixelPackedSampleModel can be used with. The new SinglePixelPackedSampleModel/DataBuffer combination will represent an image with a subset of the bands of the original SinglePixelPackedSampleModel/DataBuffer combination.

Specified by:

createSubsetSampleModel in class SampleModel

Parameters:

bands - the subset of bands of this SampleModel

Returns:

a SampleModel with a subset of bands of this SampleModel.

Throws:

RasterFormatException - if the length of the bands argument is greater than the number of bands in the sample model.

getDataElements

public Object getDataElements(int x,
                              int y,
                              Object obj,
                              DataBuffer data)

Returns data for a single pixel in a primitive array of type TransferType. For a SinglePixelPackedSampleModel, the array will have one element, and the type will be the same as the storage data type. Generally, obj should be passed in as null, so that the Object will be created automatically and will be of the right primitive data type.

The following code illustrates transferring data for one pixel from DataBuffer db1, whose storage layout is described by SinglePixelPackedSampleModel sppsm1, to DataBuffer db2, whose storage layout is described by SinglePixelPackedSampleModel sppsm2. The transfer will generally be more efficient than using getPixel/setPixel.

 	     SinglePixelPackedSampleModel sppsm1, sppsm2;
	     DataBufferInt db1, db2;
 	     sppsm2.setDataElements(x, y, sppsm1.getDataElements(x, y, null,
                              db1), db2);
 

Using getDataElements/setDataElements to transfer between two DataBuffer/SampleModel pairs is legitimate if the SampleModels have the same number of bands, corresponding bands have the same number of bits per sample, and the TransferTypes are the same.

If obj is non-null, it should be a primitive array of type TransferType. Otherwise, a ClassCastException is thrown. An ArrayIndexOutOfBoundsException may be thrown if the coordinates are not in bounds, or if obj is non-null and is not large enough to hold the pixel data.

Specified by:

getDataElements in class SampleModel

Parameters:

x - The X coordinate of the pixel location.

y - The Y coordinate of the pixel location.

obj - If non-null, a primitive array in which to return the pixel data.

data - The DataBuffer containing the image data.

Returns:

the data for the specified pixel.

See Also:

setDataElements(int, int, Object, DataBuffer)

getPixel

public int[] getPixel(int x,
                      int y,
                      int[] iArray,
                      DataBuffer data)

Returns all samples in for the specified pixel in an int array. ArrayIndexOutOfBoundsException may be thrown if the coordinates are not in bounds.

Overrides:

getPixel in class SampleModel

Parameters:

x - The X coordinate of the pixel location.

y - The Y coordinate of the pixel location.

iArray - If non-null, returns the samples in this array

data - The DataBuffer containing the image data.

Returns:

all samples for the specified pixel.

See Also:

setPixel(int, int, int[], DataBuffer)

getPixels

public int[] getPixels(int x,
                       int y,
                       int w,
                       int h,
                       int[] iArray,
                       DataBuffer data)

Returns all samples for the specified rectangle of pixels in an int array, one sample per array element. ArrayIndexOutOfBoundsException may be thrown if the coordinates are not in bounds.

Overrides:

getPixels in class SampleModel

Parameters:

x - The X coordinate of the upper left pixel location.

y - The Y coordinate of the upper left pixel location.

w - The width of the pixel rectangle.

h - The height of the pixel rectangle.

iArray - If non-null, returns the samples in this array.

data - The DataBuffer containing the image data.

Returns:

all samples for the specified region of pixels.

See Also:

setPixels(int, int, int, int, int[], DataBuffer)

getSample

public int getSample(int x,
                     int y,
                     int b,
                     DataBuffer data)

Returns as int the sample in a specified band for the pixel located at (x,y). ArrayIndexOutOfBoundsException may be thrown if the coordinates are not in bounds.

Specified by:

getSample in class SampleModel

Parameters:

x - The X coordinate of the pixel location.

y - The Y coordinate of the pixel location.

b - The band to return.

data - The DataBuffer containing the image data.

Returns:

the sample in a specified band for the specified pixel.

See Also:

setSample(int, int, int, int, DataBuffer)

getSamples

public int[] getSamples(int x,
                        int y,
                        int w,
                        int h,
                        int b,
                        int[] iArray,
                        DataBuffer data)

Returns the samples for a specified band for the specified rectangle of pixels in an int array, one sample per array element. ArrayIndexOutOfBoundsException may be thrown if the coordinates are not in bounds.

Overrides:

getSamples in class SampleModel

Parameters:

x - The X coordinate of the upper left pixel location.

y - The Y coordinate of the upper left pixel location.

w - The width of the pixel rectangle.

h - The height of the pixel rectangle.

b - The band to return.

iArray - If non-null, returns the samples in this array.

data - The DataBuffer containing the image data.

Returns:

the samples for the specified band for the specified region of pixels.

See Also:

setSamples(int, int, int, int, int, int[], DataBuffer)

setDataElements

public void setDataElements(int x,
                            int y,
                            Object obj,
                            DataBuffer data)

Sets the data for a single pixel in the specified DataBuffer from a primitive array of type TransferType. For a SinglePixelPackedSampleModel, only the first element of the array will hold valid data, and the type of the array must be the same as the storage data type of the SinglePixelPackedSampleModel.

The following code illustrates transferring data for one pixel from DataBuffer db1, whose storage layout is described by SinglePixelPackedSampleModel sppsm1, to DataBuffer db2, whose storage layout is described by SinglePixelPackedSampleModel sppsm2. The transfer will generally be more efficient than using getPixel/setPixel.

 	     SinglePixelPackedSampleModel sppsm1, sppsm2;
	     DataBufferInt db1, db2;
 	     sppsm2.setDataElements(x, y, sppsm1.getDataElements(x, y, null,
                              db1), db2);
 

Using getDataElements/setDataElements to transfer between two DataBuffer/SampleModel pairs is legitimate if the SampleModels have the same number of bands, corresponding bands have the same number of bits per sample, and the TransferTypes are the same.

obj must be a primitive array of type TransferType. Otherwise, a ClassCastException is thrown. An ArrayIndexOutOfBoundsException may be thrown if the coordinates are not in bounds, or if obj is not large enough to hold the pixel data.

Specified by:

setDataElements in class SampleModel

Parameters:

x - The X coordinate of the pixel location.

y - The Y coordinate of the pixel location.

obj - A primitive array containing pixel data.

data - The DataBuffer containing the image data.

See Also:

getDataElements(int, int, Object, DataBuffer)

setPixel

public void setPixel(int x,
                     int y,
                     int[] iArray,
                     DataBuffer data)

Sets a pixel in the DataBuffer using an int array of samples for input. ArrayIndexOutOfBoundsException may be thrown if the coordinates are not in bounds.

Overrides:

setPixel in class SampleModel

Parameters:

x - The X coordinate of the pixel location.

y - The Y coordinate of the pixel location.

iArray - The input samples in an int array.

data - The DataBuffer containing the image data.

See Also:

getPixel(int, int, int[], DataBuffer)

setPixels

public void setPixels(int x,
                      int y,
                      int w,
                      int h,
                      int[] iArray,
                      DataBuffer data)

Sets all samples for a rectangle of pixels from an int array containing one sample per array element. ArrayIndexOutOfBoundsException may be thrown if the coordinates are not in bounds.

Overrides:

setPixels in class SampleModel

Parameters:

x - The X coordinate of the upper left pixel location.

y - The Y coordinate of the upper left pixel location.

w - The width of the pixel rectangle.

h - The height of the pixel rectangle.

iArray - The input samples in an int array.

data - The DataBuffer containing the image data.

See Also:

getPixels(int, int, int, int, int[], DataBuffer)

setSample

public void setSample(int x,
                      int y,
                      int b,
                      int s,
                      DataBuffer data)

Sets a sample in the specified band for the pixel located at (x,y) in the DataBuffer using an int for input. ArrayIndexOutOfBoundsException may be thrown if the coordinates are not in bounds.

Specified by:

setSample in class SampleModel

Parameters:

x - The X coordinate of the pixel location.

y - The Y coordinate of the pixel location.

b - The band to set.

s - The input sample as an int.

data - The DataBuffer containing the image data.

See Also:

getSample(int, int, int, DataBuffer)

setSamples

public void setSamples(int x,
                       int y,
                       int w,
                       int h,
                       int b,
                       int[] iArray,
                       DataBuffer data)

Sets the samples in the specified band for the specified rectangle of pixels from an int array containing one sample per array element. ArrayIndexOutOfBoundsException may be thrown if the coordinates are not in bounds.

Overrides:

setSamples in class SampleModel

Parameters:

x - The X coordinate of the upper left pixel location.

y - The Y coordinate of the upper left pixel location.

w - The width of the pixel rectangle.

h - The height of the pixel rectangle.

b - The band to set.

iArray - The input samples in an int array.

data - The DataBuffer containing the image data.

See Also:

getSamples(int, int, int, int, int, int[], DataBuffer)

equals

public boolean equals(Object o)

Description copied from class: Object

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

• It is reflexive: for any non-null reference value x, x.equals(x) should return true.
• It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
• For any non-null reference value x, x.equals(null) should return false.

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

Overrides:

equals in class Object

Parameters:

o - the reference object with which to compare.

Returns:

true if this object is the same as the obj argument; false otherwise.

See Also:

Object.hashCode(), Hashtable

hashCode

public int hashCode()

Description copied from class: Object

Returns a hash code value for the object. This method is supported for the benefit of hashtables such as those provided by java.util.Hashtable.

The general contract of hashCode is:

• Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
• If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
• It is not required that if two objects are unequal according to the Object.equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hashtables.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java^TM programming language.)

Overrides:

hashCode in class Object

Returns:

a hash code value for this object.

See Also:

Object.equals(java.lang.Object), Hashtable