Module java.desktop
Package java.awt.image

Class 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);

    • 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.

      • 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 xth 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.

      • 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. (The hashCode may or may not be implemented as some function of an object's memory address at some point in time.)

        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)