MultiPixelPackedSampleModel (Java Platform SE 8 )
Keywords: java.awt.image.MultiPixelPackedSampleModel class
Date: 2015-11-19

java.awt.image

## 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 inherited from class java.awt.image.SampleModel

      `dataType, height, numBands, width`

  - ### Constructor Summary

    Constructors
    Constructor and 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

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and 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`.
    `boolean` | `equals(Object o)` Indicates whether some other object is "equal to" this one.
    `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.
    `int` | `hashCode()` Returns a hash code value for the object.
    `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 inherited from 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 inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### 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 Detail

    - #### 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)`

    - #### 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()`, `HashMap`

    - #### 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 hash tables such as those provided by `HashMap`.

      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 hash tables.

      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™ programming language.)

      Overrides:
        `hashCode` in class `Object`
      Returns:
        a hash code value for this object.
      See Also:
        `Object.equals(java.lang.Object)`, `System.identityHashCode(java.lang.Object)`

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