# Class MultiPixelPackedSampleModel

java.lang.Object
java.awt.image.SampleModel
java.awt.image.MultiPixelPackedSampleModel

public class MultiPixelPackedSampleModel extends SampleModel
The `MultiPixelPackedSampleModel` class represents one-banded images and can pack multiple one-sample pixels into one data element. Pixels are not allowed to span data elements. The data type can be DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT, or DataBuffer.TYPE_INT. Each pixel must be a power of 2 number of bits and a power of 2 number of pixels must fit exactly in one data element. Pixel bit stride is equal to the number of bits per pixel. Scanline stride is in data elements and the last several data elements might be padded with unused pixels. Data bit offset is the offset in bits from the beginning of the `DataBuffer` to the first pixel and must be a multiple of pixel bit stride.

The following code illustrates extracting the bits for pixel `x, y` from `DataBuffer data` and storing the pixel data in data elements of type `dataType`:

          int dataElementSize = DataBuffer.getDataTypeSize(dataType);
          int bitnum = dataBitOffset + x*pixelBitStride;
          int element = data.getElem(y*scanlineStride + bitnum/dataElementSize);
          int shift = dataElementSize - (bitnum & (dataElementSize-1))
                      - pixelBitStride;
          int pixel = (element >> shift) & ((1 << pixelBitStride) - 1);

- ## Field Summary

  ### Fields declared in class java.awt.image.SampleModel

  `dataType, height, numBands, width`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `MultiPixelPackedSampleModel(int dataType, int w, int h, int numberOfBits)`
  Constructs a `MultiPixelPackedSampleModel` with the specified data type, width, height and number of bits per pixel.
  `MultiPixelPackedSampleModel(int dataType, int w, int h, int numberOfBits, int scanlineStride, int dataBitOffset)`
  Constructs a `MultiPixelPackedSampleModel` with specified data type, width, height, number of bits per pixel, scanline stride and data bit offset.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `SampleModel`
  `createCompatibleSampleModel(int w, int h)`
  Creates a new `MultiPixelPackedSampleModel` with the specified width and height.
  `DataBuffer`
  `createDataBuffer()`
  Creates a `DataBuffer` that corresponds to this `MultiPixelPackedSampleModel`.
  `SampleModel`
  `createSubsetSampleModel(int[] bands)`
  Creates a new `MultiPixelPackedSampleModel` with a subset of the bands of this `MultiPixelPackedSampleModel`.
  `int`
  `getBitOffset(int x)`
  Returns the offset, in bits, into the data element in which it is stored for the `x`th pixel of a scanline.
  `int`
  `getDataBitOffset()`
  Returns the data bit offset in bits.
  `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(int, int, java.lang.Object, java.awt.image.DataBuffer)` and `setDataElements(int, int, java.lang.Object, java.awt.image.DataBuffer)` methods.
  `int`
  `getOffset(int x, int y)`
  Returns the offset of pixel (x, y) in data array elements.
  `int[]`
  `getPixel(int x, int y, int[] iArray, DataBuffer data)`
  Returns the specified single band pixel in the first element of an `int` array.
  `int`
  `getPixelBitStride()`
  Returns the pixel bit stride in bits.
  `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[]`
  `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.
  `int`
  `getTransferType()`
  Returns the TransferType used to transfer pixels by way of the `getDataElements` and `setDataElements` methods.
  `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 for input.
  `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.

  ### Methods declared in class java.awt.image.SampleModel

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

  ### Methods declared in class java.lang.Object

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

- ## Constructor Details

  - ### MultiPixelPackedSampleModel

    public MultiPixelPackedSampleModel(int dataType, int w, int h, int numberOfBits)
    Constructs a `MultiPixelPackedSampleModel` with the specified data type, width, height and number of bits per pixel.
    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
      `numberOfBits` - the number of bits per pixel
    Throws:
      `IllegalArgumentException` - if `dataType` is not either `DataBuffer.TYPE_BYTE`, `DataBuffer.TYPE_USHORT`, or `DataBuffer.TYPE_INT`

  - ### MultiPixelPackedSampleModel

    public MultiPixelPackedSampleModel(int dataType, int w, int h, int numberOfBits, int scanlineStride, int dataBitOffset)
    Constructs a `MultiPixelPackedSampleModel` with specified data type, width, height, number of bits per pixel, scanline stride and data bit offset.
    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
      `numberOfBits` - the number of bits per pixel
      `scanlineStride` - the line stride of the image data
      `dataBitOffset` - the data bit offset for the region of image data described
    Throws:
      `RasterFormatException` - if the number of bits per pixel is not a power of 2 or if a power of 2 number of pixels do not fit in one data element.
      `IllegalArgumentException` - if `w` or `h` is not greater than 0
      `IllegalArgumentException` - if `dataType` is not either `DataBuffer.TYPE_BYTE`, `DataBuffer.TYPE_USHORT`, or `DataBuffer.TYPE_INT`

- ## Method Details

  - ### createCompatibleSampleModel

    public SampleModel createCompatibleSampleModel(int w, int h)
    Creates a new `MultiPixelPackedSampleModel` with the specified width and height. The new `MultiPixelPackedSampleModel` has the same storage data type and number of bits per pixel as this `MultiPixelPackedSampleModel`.
    Specified by:
      `createCompatibleSampleModel` in class `SampleModel`
    Parameters:
      `w` - the specified width
      `h` - the specified height
    Returns:
      a `SampleModel` with the specified width and height and with the same storage data type and number of bits per pixel as this `MultiPixelPackedSampleModel`.
    Throws:
      `IllegalArgumentException` - if `w` or `h` is not greater than 0

  - ### createDataBuffer

    public DataBuffer createDataBuffer()
    Creates a `DataBuffer` that corresponds to this `MultiPixelPackedSampleModel`. The `DataBuffer` object's data type and size is consistent with this `MultiPixelPackedSampleModel`. The `DataBuffer` has a single bank.
    Specified by:
      `createDataBuffer` in class `SampleModel`
    Returns:
      a `DataBuffer` with the same data type and size as this `MultiPixelPackedSampleModel`.

  - ### getNumDataElements

    public int getNumDataElements()
    Returns the number of data elements needed to transfer one pixel via the `getDataElements(int, int, java.lang.Object, java.awt.image.DataBuffer)` and `setDataElements(int, int, java.lang.Object, java.awt.image.DataBuffer)` methods. For a `MultiPixelPackedSampleModel`, 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()`

  - ### getSampleSize

    public int[] getSampleSize()
    Returns the number of bits per sample for all bands.
    Specified by:
      `getSampleSize` in class `SampleModel`
    Returns:
      the number of bits per sample.

  - ### 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 number of bits per sample for the specified band.

  - ### getOffset

    public int getOffset(int x, int y)
    Returns the offset of pixel (x, y) in data array elements.
    Parameters:
      `x` - the X coordinate of the specified pixel
      `y` - the Y coordinate of the specified pixel
    Returns:
      the offset of the specified pixel.

  - ### getBitOffset

    public int getBitOffset(int x)
    Returns the offset, in bits, into the data element in which it is stored for the `x`th pixel of a scanline. This offset is the same for all scanlines.
    Parameters:
      `x` - the specified pixel
    Returns:
      the bit offset of the specified pixel.

  - ### getScanlineStride

    public int getScanlineStride()
    Returns the scanline stride.
    Returns:
      the scanline stride of this `MultiPixelPackedSampleModel`.

  - ### getPixelBitStride

    public int getPixelBitStride()
    Returns the pixel bit stride in bits. This value is the same as the number of bits per pixel.
    Returns:
      the `pixelBitStride` of this `MultiPixelPackedSampleModel`.

  - ### getDataBitOffset

    public int getDataBitOffset()
    Returns the data bit offset in bits.
    Returns:
      the `dataBitOffset` of this `MultiPixelPackedSampleModel`.

  - ### getTransferType

    public int getTransferType()
    Returns the TransferType used to transfer pixels by way of the `getDataElements` and `setDataElements` methods. The TransferType might or might not be the same as the storage DataType. The TransferType is one of DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT, or DataBuffer.TYPE_INT.
    Overrides:
      `getTransferType` in class `SampleModel`
    Returns:
      the transfertype.
    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.getNumDataElements()`
      - `DataBuffer`

  - ### createSubsetSampleModel

    public SampleModel createSubsetSampleModel(int[] bands)
    Creates a new `MultiPixelPackedSampleModel` with a subset of the bands of this `MultiPixelPackedSampleModel`. Since a `MultiPixelPackedSampleModel` only has one band, the bands argument must have a length of one and indicate the zeroth band.
    Specified by:
      `createSubsetSampleModel` in class `SampleModel`
    Parameters:
      `bands` - the specified bands
    Returns:
      a new `SampleModel` with a subset of bands of this `MultiPixelPackedSampleModel`.
    Throws:
      `RasterFormatException` - if the number of bands requested is not one.
      `IllegalArgumentException` - if `w` or `h` is not greater than 0

  - ### 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). An `ArrayIndexOutOfBoundsException` is thrown if the coordinates are not in bounds.
    Specified by:
      `getSample` in class `SampleModel`
    Parameters:
      `x` - the X coordinate of the specified pixel
      `y` - the Y coordinate of the specified pixel
      `b` - the band to return, which is assumed to be 0
      `data` - the `DataBuffer` containing the image data
    Returns:
      the specified band containing the sample of the specified pixel.
    Throws:
      `ArrayIndexOutOfBoundsException` - if the specified coordinates are not in bounds.
    See Also:
      - `setSample(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. An `ArrayIndexOutOfBoundsException` is thrown if the coordinates are not in bounds.
    Specified by:
      `setSample` in class `SampleModel`
    Parameters:
      `x` - the X coordinate of the specified pixel
      `y` - the Y coordinate of the specified pixel
      `b` - the band to return, which is assumed to be 0
      `s` - the input sample as an `int`
      `data` - the `DataBuffer` where image data is stored
    Throws:
      `ArrayIndexOutOfBoundsException` - if the coordinates are not in bounds.
    See Also:
      - `getSample(int, int, int, DataBuffer)`

  - ### 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 `MultiPixelPackedSampleModel`, the array has one element, and the type is the smallest of DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT, or DataBuffer.TYPE_INT that can hold a single pixel. Generally, `obj` should be passed in as `null`, so that the `Object` is created automatically and is the correct primitive data type.

    The following code illustrates transferring data for one pixel from `DataBuffer db1`, whose storage layout is described by `MultiPixelPackedSampleModel` `mppsm1`, to `DataBuffer db2`, whose storage layout is described by `MultiPixelPackedSampleModel mppsm2`. The transfer is generally more efficient than using `getPixel` or `setPixel`.

               MultiPixelPackedSampleModel mppsm1, mppsm2;
               DataBufferInt db1, db2;
               mppsm2.setDataElements(x, y, mppsm1.getDataElements(x, y, null,
                                      db1), db2);

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

    Specified by:
      `getDataElements` in class `SampleModel`
    Parameters:
      `x` - the X coordinate of the specified pixel
      `y` - the Y coordinate of the specified pixel
      `obj` - a primitive array in which to return the pixel data or `null`.
      `data` - the `DataBuffer` containing the image data.
    Returns:
      an `Object` containing data for the specified pixel.
    Throws:
      `ClassCastException` - if `obj` is not a primitive array of type TransferType or is not `null`
      `ArrayIndexOutOfBoundsException` - if the coordinates are not in bounds, or if `obj` is not `null` or not large enough to hold the pixel data
    See Also:
      - `setDataElements(int, int, Object, DataBuffer)`

  - ### getPixel

    public int[] getPixel(int x, int y, int[] iArray, DataBuffer data)
    Returns the specified single band pixel in the first element of an `int` array. `ArrayIndexOutOfBoundsException` is thrown if the coordinates are not in bounds.
    Overrides:
      `getPixel` in class `SampleModel`
    Parameters:
      `x` - the X coordinate of the specified pixel
      `y` - the Y coordinate of the specified pixel
      `iArray` - the array containing the pixel to be returned or `null`
      `data` - the `DataBuffer` where image data is stored
    Returns:
      an array containing the specified pixel.
    Throws:
      `ArrayIndexOutOfBoundsException` - if the coordinates are not in bounds
    See Also:
      - `setPixel(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 `MultiPixelPackedSampleModel`, only the first element of the array holds valid data, and the type must be the smallest of DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT, or DataBuffer.TYPE_INT that can hold a single pixel.

    The following code illustrates transferring data for one pixel from `DataBuffer db1`, whose storage layout is described by `MultiPixelPackedSampleModel` `mppsm1`, to `DataBuffer db2`, whose storage layout is described by `MultiPixelPackedSampleModel mppsm2`. The transfer is generally more efficient than using `getPixel` or `setPixel`.

               MultiPixelPackedSampleModel mppsm1, mppsm2;
               DataBufferInt db1, db2;
               mppsm2.setDataElements(x, y, mppsm1.getDataElements(x, y, null,
                                      db1), db2);

    Using `getDataElements` or `setDataElements` to transfer between two `DataBuffer/SampleModel` pairs is legitimate if the `SampleModel` objects 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` is 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 for input. `ArrayIndexOutOfBoundsException` is 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 pixel in an `int` array
      `data` - the `DataBuffer` containing the image data
    See Also:
      - `getPixel(int, int, int[], DataBuffer)`