Class TIFFDecompressor

java.lang.Object
com.github.jaiimageio.plugins.tiff.TIFFDecompressor
Direct Known Subclasses:
TIFFDeflateDecompressor, TIFFFaxDecompressor, TIFFJPEGDecompressor, TIFFLSBDecompressor, TIFFLZWDecompressor, TIFFNullDecompressor, TIFFPackBitsDecompressor, TIFFYCbCrDecompressor

public abstract class TIFFDecompressor extends Object
A class defining a pluggable TIFF decompressor.

The mapping between source and destination Y coordinates is given by the equations:

 dx = (sx - sourceXOffset)/subsampleX + dstXOffset;
 dy = (sy - sourceYOffset)/subsampleY + dstYOffset;
 
Note that the mapping from source coordinates to destination coordinates is not one-to-one if subsampling is being used, since only certain source pixels are to be copied to the destination. However, * the inverse mapping is always one-to-one:
 sx = (dx - dstXOffset)*subsampleX + sourceXOffset;
 sy = (dy - dstYOffset)*subsampleY + sourceYOffset;
 

Decompressors may be written with various levels of complexity. The most complex decompressors will override the decode method, and will perform all the work of decoding, subsampling, offsetting, clipping, and format conversion. This approach may be the most efficient, since it is possible to avoid the use of extra image buffers, and it may be possible to avoid decoding portions of the image that will not be copied into the destination.

Less ambitious decompressors may override the decodeRaw method, which is responsible for decompressing the entire tile or strip into a byte array (or other appropriate datatype). The default implementation of decode will perform all necessary setup of buffers, call decodeRaw to perform the actual decoding, perform subsampling, and copy the results into the final destination image. Where possible, it will pass the real image buffer to decodeRaw in order to avoid making an extra copy.

Slightly more ambitious decompressors may override decodeRaw, but avoid writing pixels that will be discarded in the subsampling phase.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected int
    The height of the source region that will actually be copied into the destination image, taking into account all susbampling, offsetting, and clipping.
    protected int
    The X coordinate of the upper-left source pixel that will actually be copied into the destination image, taking into account all subsampling, offsetting, and clipping.
    protected int
    The Y coordinate of the upper-left source pixel that will actually be copied into the destination image, taking into account all subsampling, offsetting, and clipping.
    protected int
    The width of the source region that will actually be copied into the destination image, taking into account all susbampling, offsetting, and clipping.
    (package private) boolean
     
    (package private) int[][]
     
    protected int[]
    The value of the BitsPerSample tag.
    private int[]
     
    protected int
    The number of bytes of data from the source ImageInputStream to be decompressed.
    A TIFFColorConverter object describing the color space of the encoded pixel data, or null.
    protected char[]
    The value of the ColorMap tag.
    protected int
    The value of the Compression tag.
    private static final boolean
     
    private int[]
     
    protected int[]
    The sequence of destination bands to receive the source data.
    private int[]
     
    protected int
    The height of the region of the destination image to be written.
    protected int
    The X coordinate of the upper left pixel to be written in the destination image.
    protected int
    The Y coordinate of the upper left pixel to be written in the destination image.
    protected int
    The width of the region of the destination image to be written.
    protected int
    The horizontal destination offset used, along with sourceXOffset and subsampleX, to map between horizontal source and destination pixel coordinates.
    protected int
    The vertical destination offset used, along with sourceYOffset and subsampleY, to map between horizontal source and destination pixel coordinates.
    protected int[]
    The value of the ExtraSamples tag.
    protected BufferedImage
    The final destination image.
    (package private) boolean
     
    (package private) boolean
     
    private boolean
     
    (package private) boolean
     
    protected IIOMetadata
    The IIOMetadata object containing metadata for the current image.
    protected long
    The offset in the source ImageInputStream of the start of the data to be decompressed.
    protected int
    The value of the PhotometricInterpretation tag.
    protected boolean
    true if the image is encoded using separate planes.
    private boolean
     
    protected BufferedImage
    A BufferedImage for the decodeRaw method to write into.
    protected ImageReader
    The ImageReader calling this TIFFDecompressor.
    protected int[]
    The value of the SampleFormat tag.
    protected int
    The value of the SamplesPerPixel tag.
    protected int[]
    The sequence of source bands that are to be copied into the destination.
    private int[]
     
    protected int
    The source X offset used, along with dstXOffset and subsampleX, to map between horizontal source and destination pixel coordinates.
    protected int
    The source Y offset used, along with dstYOffset and subsampleY, to map between vertical source and destination pixel coordinates.
    protected int
    The height of the source region being decoded from the source stream.
    protected int
    The X coordinate of the upper-left pixel of the source region being decoded from the source stream.
    protected int
    The Y coordinate of the upper-left pixel of the source region being decoded from the source stream.
    protected int
    The width of the source region being decoded from the source stream.
    The ImageInputStream containing the TIFF source data.
    protected int
    The horizontal subsampling factor.
    protected int
    The vertical subsampling factor.
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    private static boolean
    areIntArraysEqual(int[] a, int[] b)
     
    private static boolean
    Returns whether all samples have the same number of bits.
    void
    This routine is called prior to a sequence of calls to the decode method, in order to allow any necessary tables or other structures to be initialized based on metadata values.
    (package private) static ColorModel
    createComponentCM(ColorSpace colorSpace, int numBands, int dataType, boolean hasAlpha, boolean isAlphaPremultiplied)
    Create a ComponentColorModel for use in creating an ImageTypeSpecifier.
    (package private) static SampleModel
    createInterleavedSM(int dataType, int numBands)
    Create a PixelInterleavedSampleModel for use in creating an ImageTypeSpecifier.
    private static int
    createMask(int[] bitsPerSample, int band)
     
    Creates a BufferedImage whose underlying data array will be suitable for holding the raw decoded output of the decodeRaw method.
    void
    Decodes the input bit stream (located in the ImageInputStream stream, at offset offset, and continuing for byteCount bytes) into the output BufferedImage image.
    abstract void
    decodeRaw(byte[] b, int dstOffset, int bitsPerPixel, int scanlineStride)
    Decodes the source data into the provided byte array b, starting at the offset given by dstOffset.
    void
    decodeRaw(float[] f, int dstOffset, int bitsPerPixel, int scanlineStride)
    Decodes the source data into the provided float array f, starting at the offset given by dstOffset.
    void
    decodeRaw(int[] i, int dstOffset, int bitsPerPixel, int scanlineStride)
    Decodes the source data into the provided int array i, starting at the offset given by dstOffset.
    void
    decodeRaw(short[] s, int dstOffset, int bitsPerPixel, int scanlineStride)
    Decodes the source data into the provided short array s, starting at the offset given by dstOffset.
    private static int
    Returns the number of bits per pixel.
    private static int
    getDataTypeFromNumBits(int numBits, boolean isSigned)
     
    private static int
    getDataTypeSize(int dataType)
    Return the number of bits occupied by dataType which must be one of the DataBuffer TYPEs.
    Returns an ImageTypeSpecifier describing an image whose underlying data array has the same format as the raw source pixel data.
    getRawImageTypeSpecifier(int photometricInterpretation, int compression, int samplesPerPixel, int[] bitsPerSample, int[] sampleFormat, int[] extraSamples, char[] colorMap)
    A utility method that returns an ImageTypeSpecifier suitable for decoding an image with the given parameters.
    private static boolean
    Determines whether the DataBuffer is filled without any interspersed padding bits.
    private static void
    reformatData(byte[] buf, int bytesPerRow, int numRows, short[] shortData, int[] intData, int outOffset, int outStride)
    Reformats data read as bytes into a short or int buffer.
    private static void
    reformatDiscontiguousData(byte[] buf, int stride, int w, int h, WritableRaster raster)
    Reformats bit-discontiguous data into the DataBuffer of the supplied WritableRaster.
    void
    setActiveSrcHeight(int activeSrcHeight)
    Sets the value of the activeSrcHeight field.
    void
    setActiveSrcMinX(int activeSrcMinX)
    Sets the value of the activeSrcMinX field.
    void
    setActiveSrcMinY(int activeSrcMinY)
    Sets the value of the activeSrcMinY field.
    void
    setActiveSrcWidth(int activeSrcWidth)
    Sets the value of the activeSrcWidth field.
    void
    setBitsPerSample(int[] bitsPerSample)
    Sets the value of the bitsPerSample field.
    void
    setByteCount(int byteCount)
    Sets the value of the byteCount field.
    void
    Sets the TIFFColorConverter object describing the color space of the encoded data in the input stream.
    void
    setColorMap(char[] colorMap)
    Sets the value of the colorMap field.
    void
    setCompression(int compression)
    Sets the value of the compression field.
    void
    setDestinationBands(int[] destinationBands)
    Sets the value of the destinationBands field.
    void
    setDstHeight(int dstHeight)
    Sets the value of the dstHeight field.
    void
    setDstMinX(int dstMinX)
    Sets the value of the dstMinX field.
    void
    setDstMinY(int dstMinY)
    Sets the value of the dstMinY field.
    void
    setDstWidth(int dstWidth)
    Sets the value of the dstWidth field.
    void
    setDstXOffset(int dstXOffset)
    Sets the value of the dstXOffset field.
    void
    setDstYOffset(int dstYOffset)
    Sets the value of the dstYOffset field.
    void
    setExtraSamples(int[] extraSamples)
    Sets the value of the extraSamples field.
    void
    Sets the value of the image field.
    void
    Sets the value of the metadata field.
    void
    setOffset(long offset)
    Sets the value of the offset field.
    void
    setPhotometricInterpretation(int photometricInterpretation)
    Sets the value of the photometricInterpretation field.
    void
    setPlanar(boolean planar)
    Sets the value of the planar field.
    void
    Sets the value of the reader field.
    void
    setSampleFormat(int[] sampleFormat)
    Sets the value of the sampleFormat field.
    void
    setSamplesPerPixel(int samplesPerPixel)
    Sets the value of the samplesPerPixel field.
    void
    setSourceBands(int[] sourceBands)
    Sets the value of the sourceBands field.
    void
    setSourceXOffset(int sourceXOffset)
    Sets the value of the sourceXOffset field.
    void
    setSourceYOffset(int sourceYOffset)
    Sets the value of the sourceYOffset.
    void
    setSrcHeight(int srcHeight)
    Sets the value of the srcHeight field.
    void
    setSrcMinX(int srcMinX)
    Sets the value of the srcMinX field.
    void
    setSrcMinY(int srcMinY)
    Sets the value of the srcMinY field.
    void
    setSrcWidth(int srcWidth)
    Sets the value of the srcWidth field.
    void
    Sets the value of the stream field.
    void
    setSubsampleX(int subsampleX)
    Sets the value of the subsampleX field.
    void
    setSubsampleY(int subsampleY)
    Sets the value of the subsampleY field.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • DEBUG

      private static final boolean DEBUG
      See Also:
    • reader

      protected ImageReader reader
      The ImageReader calling this TIFFDecompressor.
    • metadata

      protected IIOMetadata metadata
      The IIOMetadata object containing metadata for the current image.
    • photometricInterpretation

      protected int photometricInterpretation
    • compression

      protected int compression
    • planar

      protected boolean planar
      true if the image is encoded using separate planes.
    • samplesPerPixel

      protected int samplesPerPixel
      The value of the SamplesPerPixel tag.
    • bitsPerSample

      protected int[] bitsPerSample
      The value of the BitsPerSample tag.
    • sampleFormat

      protected int[] sampleFormat
    • extraSamples

      protected int[] extraSamples
      The value of the ExtraSamples tag. Legal values are BaselineTIFFTagSet.EXTRA_SAMPLES_UNSPECIFIED, BaselineTIFFTagSet.EXTRA_SAMPLES_ASSOCIATED_ALPHA, BaselineTIFFTagSet.EXTRA_SAMPLES_UNASSOCIATED_ALPHA, or other value defined by a TIFF extension.
    • colorMap

      protected char[] colorMap
      The value of the ColorMap tag.
    • stream

      protected ImageInputStream stream
      The ImageInputStream containing the TIFF source data.
    • offset

      protected long offset
      The offset in the source ImageInputStream of the start of the data to be decompressed.
    • byteCount

      protected int byteCount
      The number of bytes of data from the source ImageInputStream to be decompressed.
    • srcMinX

      protected int srcMinX
      The X coordinate of the upper-left pixel of the source region being decoded from the source stream. This value is not affected by source subsampling.
    • srcMinY

      protected int srcMinY
      The Y coordinate of the upper-left pixel of the source region being decoded from the source stream. This value is not affected by source subsampling.
    • srcWidth

      protected int srcWidth
      The width of the source region being decoded from the source stream. This value is not affected by source subsampling.
    • srcHeight

      protected int srcHeight
      The height of the source region being decoded from the source stream. This value is not affected by source subsampling.
    • sourceXOffset

      protected int sourceXOffset
      The source X offset used, along with dstXOffset and subsampleX, to map between horizontal source and destination pixel coordinates.
    • dstXOffset

      protected int dstXOffset
      The horizontal destination offset used, along with sourceXOffset and subsampleX, to map between horizontal source and destination pixel coordinates. See the comment for sourceXOffset for the mapping equations.
    • sourceYOffset

      protected int sourceYOffset
      The source Y offset used, along with dstYOffset and subsampleY, to map between vertical source and destination pixel coordinates.
    • dstYOffset

      protected int dstYOffset
      The vertical destination offset used, along with sourceYOffset and subsampleY, to map between horizontal source and destination pixel coordinates. See the comment for sourceYOffset for the mapping equations.
    • subsampleX

      protected int subsampleX
      The horizontal subsampling factor. A factor of 1 means that every column is copied to the destination; a factor of 2 means that every second column is copied, etc.
    • subsampleY

      protected int subsampleY
      The vertical subsampling factor. A factor of 1 means that every row is copied to the destination; a factor of 2 means that every second row is copied, etc.
    • sourceBands

      protected int[] sourceBands
      The sequence of source bands that are to be copied into the destination.
    • destinationBands

      protected int[] destinationBands
      The sequence of destination bands to receive the source data.
    • rawImage

      protected BufferedImage rawImage
      A BufferedImage for the decodeRaw method to write into.
    • image

      protected BufferedImage image
      The final destination image.
    • dstMinX

      protected int dstMinX
      The X coordinate of the upper left pixel to be written in the destination image.
    • dstMinY

      protected int dstMinY
      The Y coordinate of the upper left pixel to be written in the destination image.
    • dstWidth

      protected int dstWidth
      The width of the region of the destination image to be written.
    • dstHeight

      protected int dstHeight
      The height of the region of the destination image to be written.
    • activeSrcMinX

      protected int activeSrcMinX
      The X coordinate of the upper-left source pixel that will actually be copied into the destination image, taking into account all subsampling, offsetting, and clipping. That is, the pixel at (activeSrcMinX, activeSrcMinY) is to be copied into the destination pixel at (dstMinX, dstMinY).

      The pixels in the source region to be copied are those with X coordinates of the form activeSrcMinX + k*subsampleX, where k is an integer such that 0 invalid input: '<'= k invalid input: '<' dstWidth.

    • activeSrcMinY

      protected int activeSrcMinY
      The Y coordinate of the upper-left source pixel that will actually be copied into the destination image, taking into account all subsampling, offsetting, and clipping.

      The pixels in the source region to be copied are those with Y coordinates of the form activeSrcMinY + k*subsampleY, where k is an integer such that 0 invalid input: '<'= k invalid input: '<' dstHeight.

    • activeSrcWidth

      protected int activeSrcWidth
      The width of the source region that will actually be copied into the destination image, taking into account all susbampling, offsetting, and clipping.

      The active source width will always be equal to (dstWidth - 1)*subsampleX + 1.

    • activeSrcHeight

      protected int activeSrcHeight
      The height of the source region that will actually be copied into the destination image, taking into account all susbampling, offsetting, and clipping.

      The active source height will always be equal to (dstHeight - 1)*subsampleY + 1.

    • colorConverter

      protected TIFFColorConverter colorConverter
      A TIFFColorConverter object describing the color space of the encoded pixel data, or null.
    • isBilevel

      boolean isBilevel
    • isContiguous

      boolean isContiguous
    • isImageSimple

      boolean isImageSimple
    • adjustBitDepths

      boolean adjustBitDepths
    • bitDepthScale

      int[][] bitDepthScale
    • isFirstBitDepthTable

      private boolean isFirstBitDepthTable
    • planarCache

      private boolean planarCache
    • destBitsPerSampleCache

      private int[] destBitsPerSampleCache
    • sourceBandsCache

      private int[] sourceBandsCache
    • bitsPerSampleCache

      private int[] bitsPerSampleCache
    • destinationBandsCache

      private int[] destinationBandsCache
  • Constructor Details

    • TIFFDecompressor

      public TIFFDecompressor()
  • Method Details

    • createInterleavedSM

      static SampleModel createInterleavedSM(int dataType, int numBands)
      Create a PixelInterleavedSampleModel for use in creating an ImageTypeSpecifier. Its dimensions will be 1x1 and it will have ascending band offsets as {0, 1, 2, ..., numBands}.
      Parameters:
      dataType - The data type (DataBuffer.TYPE_*).
      numBands - The number of bands.
      Returns:
      A PixelInterleavedSampleModel.
    • createComponentCM

      static ColorModel createComponentCM(ColorSpace colorSpace, int numBands, int dataType, boolean hasAlpha, boolean isAlphaPremultiplied)
      Create a ComponentColorModel for use in creating an ImageTypeSpecifier.
    • createMask

      private static int createMask(int[] bitsPerSample, int band)
    • getDataTypeFromNumBits

      private static int getDataTypeFromNumBits(int numBits, boolean isSigned)
    • areIntArraysEqual

      private static boolean areIntArraysEqual(int[] a, int[] b)
    • getDataTypeSize

      private static int getDataTypeSize(int dataType) throws IIOException
      Return the number of bits occupied by dataType which must be one of the DataBuffer TYPEs.
      Throws:
      IIOException
    • getBitsPerPixel

      private static int getBitsPerPixel(SampleModel sm)
      Returns the number of bits per pixel.
    • areSampleSizesEqual

      private static boolean areSampleSizesEqual(SampleModel sm)
      Returns whether all samples have the same number of bits.
    • isDataBufferBitContiguous

      private static boolean isDataBufferBitContiguous(SampleModel sm) throws IIOException
      Determines whether the DataBuffer is filled without any interspersed padding bits.
      Throws:
      IIOException
    • reformatData

      private static void reformatData(byte[] buf, int bytesPerRow, int numRows, short[] shortData, int[] intData, int outOffset, int outStride) throws IIOException
      Reformats data read as bytes into a short or int buffer.
      Throws:
      IIOException
    • reformatDiscontiguousData

      private static void reformatDiscontiguousData(byte[] buf, int stride, int w, int h, WritableRaster raster) throws IOException
      Reformats bit-discontiguous data into the DataBuffer of the supplied WritableRaster.
      Throws:
      IOException
    • getRawImageTypeSpecifier

      public static ImageTypeSpecifier getRawImageTypeSpecifier(int photometricInterpretation, int compression, int samplesPerPixel, int[] bitsPerSample, int[] sampleFormat, int[] extraSamples, char[] colorMap)
      A utility method that returns an ImageTypeSpecifier suitable for decoding an image with the given parameters.
      Parameters:
      photometricInterpretation - the value of the PhotometricInterpretation field.
      compression - the value of the Compression field.
      samplesPerPixel - the value of the SamplesPerPixel field.
      bitsPerSample - the value of the BitsPerSample field.
      sampleFormat - the value of the SampleFormat field.
      extraSamples - the value of the ExtraSamples field.
      colorMap - the value of the ColorMap field.
      Returns:
      a suitable ImageTypeSpecifier, or null if it is not possible to create one.
    • setReader

      public void setReader(ImageReader reader)
      Sets the value of the reader field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      reader - the current ImageReader.
    • setMetadata

      public void setMetadata(IIOMetadata metadata)
      Sets the value of the metadata field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      metadata - the IIOMetadata object for the image being read.
    • setPhotometricInterpretation

      public void setPhotometricInterpretation(int photometricInterpretation)
      Sets the value of the photometricInterpretation field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      photometricInterpretation - the photometric interpretation value.
    • setCompression

      public void setCompression(int compression)
      Sets the value of the compression field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      compression - the compression type.
    • setPlanar

      public void setPlanar(boolean planar)
      Sets the value of the planar field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      planar - true if the image to be decoded is stored in planar format.
    • setSamplesPerPixel

      public void setSamplesPerPixel(int samplesPerPixel)
      Sets the value of the samplesPerPixel field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      samplesPerPixel - the number of samples in each source pixel.
    • setBitsPerSample

      public void setBitsPerSample(int[] bitsPerSample)
      Sets the value of the bitsPerSample field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      bitsPerSample - the number of bits for each source image sample.
    • setSampleFormat

      public void setSampleFormat(int[] sampleFormat)
      Sets the value of the sampleFormat field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      sampleFormat - the format of the source image data, for example unsigned integer or floating-point.
    • setExtraSamples

      public void setExtraSamples(int[] extraSamples)
      Sets the value of the extraSamples field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      extraSamples - the interpretation of any samples in the source file beyond those used for basic color or grayscale information.
    • setColorMap

      public void setColorMap(char[] colorMap)
      Sets the value of the colorMap field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      colorMap - the color map to apply to the source data, as an array of chars.
    • setStream

      public void setStream(ImageInputStream stream)
      Sets the value of the stream field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      stream - the ImageInputStream to be read.
    • setOffset

      public void setOffset(long offset)
      Sets the value of the offset field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      offset - the offset of the beginning of the compressed data.
    • setByteCount

      public void setByteCount(int byteCount)
      Sets the value of the byteCount field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      byteCount - the number of bytes of compressed data.
    • setSrcMinX

      public void setSrcMinX(int srcMinX)
      Sets the value of the srcMinX field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      srcMinX - the minimum X coordinate of the source region being decoded, irrespective of how it will be copied into the destination.
    • setSrcMinY

      public void setSrcMinY(int srcMinY)
      Sets the value of the srcMinY field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      srcMinY - the minimum Y coordinate of the source region being decoded, irrespective of how it will be copied into the destination.
    • setSrcWidth

      public void setSrcWidth(int srcWidth)
      Sets the value of the srcWidth field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      srcWidth - the width of the source region being decoded, irrespective of how it will be copied into the destination.
    • setSrcHeight

      public void setSrcHeight(int srcHeight)
      Sets the value of the srcHeight field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      srcHeight - the height of the source region being decoded, irrespective of how it will be copied into the destination.
    • setSourceXOffset

      public void setSourceXOffset(int sourceXOffset)
      Sets the value of the sourceXOffset field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      sourceXOffset - the horizontal source offset to be used when mapping between source and destination coordinates.
    • setDstXOffset

      public void setDstXOffset(int dstXOffset)
      Sets the value of the dstXOffset field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      dstXOffset - the horizontal destination offset to be used when mapping between source and destination coordinates.
    • setSourceYOffset

      public void setSourceYOffset(int sourceYOffset)
      Sets the value of the sourceYOffset.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      sourceYOffset - the vertical source offset to be used when mapping between source and destination coordinates.
    • setDstYOffset

      public void setDstYOffset(int dstYOffset)
      Sets the value of the dstYOffset field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      dstYOffset - the vertical destination offset to be used when mapping between source and destination coordinates.
    • setSubsampleX

      public void setSubsampleX(int subsampleX)
      Sets the value of the subsampleX field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      subsampleX - the horizontal subsampling factor.
      Throws:
      IllegalArgumentException - if subsampleX is less than or equal to 0.
    • setSubsampleY

      public void setSubsampleY(int subsampleY)
      Sets the value of the subsampleY field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      subsampleY - the vertical subsampling factor.
      Throws:
      IllegalArgumentException - if subsampleY is less than or equal to 0.
    • setSourceBands

      public void setSourceBands(int[] sourceBands)
      Sets the value of the sourceBands field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      sourceBands - an array of ints specifying the source bands to be read.
    • setDestinationBands

      public void setDestinationBands(int[] destinationBands)
      Sets the value of the destinationBands field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      destinationBands - an array of ints specifying the destination bands to be written.
    • setImage

      public void setImage(BufferedImage image)
      Sets the value of the image field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      image - the destination BufferedImage.
    • setDstMinX

      public void setDstMinX(int dstMinX)
      Sets the value of the dstMinX field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      dstMinX - the minimum X coordinate of the destination region.
    • setDstMinY

      public void setDstMinY(int dstMinY)
      Sets the value of the dstMinY field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      dstMinY - the minimum Y coordinate of the destination region.
    • setDstWidth

      public void setDstWidth(int dstWidth)
      Sets the value of the dstWidth field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      dstWidth - the width of the destination region.
    • setDstHeight

      public void setDstHeight(int dstHeight)
      Sets the value of the dstHeight field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      dstHeight - the height of the destination region.
    • setActiveSrcMinX

      public void setActiveSrcMinX(int activeSrcMinX)
      Sets the value of the activeSrcMinX field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      activeSrcMinX - the minimum X coordinate of the active source region.
    • setActiveSrcMinY

      public void setActiveSrcMinY(int activeSrcMinY)
      Sets the value of the activeSrcMinY field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      activeSrcMinY - the minimum Y coordinate of the active source region.
    • setActiveSrcWidth

      public void setActiveSrcWidth(int activeSrcWidth)
      Sets the value of the activeSrcWidth field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      activeSrcWidth - the width of the active source region.
    • setActiveSrcHeight

      public void setActiveSrcHeight(int activeSrcHeight)
      Sets the value of the activeSrcHeight field.

      If this method is called, the beginDecoding method must be called prior to calling any of the decode methods.

      Parameters:
      activeSrcHeight - the height of the active source region.
    • setColorConverter

      public void setColorConverter(TIFFColorConverter colorConverter)
      Sets the TIFFColorConverter object describing the color space of the encoded data in the input stream. If no TIFFColorConverter is set, no conversion will be performed.
      Parameters:
      colorConverter - a TIFFColorConverter object, or null.
    • getRawImageType

      public ImageTypeSpecifier getRawImageType()
      Returns an ImageTypeSpecifier describing an image whose underlying data array has the same format as the raw source pixel data.
      Returns:
      an ImageTypeSpecifier.
    • createRawImage

      public BufferedImage createRawImage()
      Creates a BufferedImage whose underlying data array will be suitable for holding the raw decoded output of the decodeRaw method.

      The default implementation calls getRawImageType, and calls the resulting ImageTypeSpecifier's createBufferedImage method.

      Returns:
      a BufferedImage whose underlying data array has the same format as the raw source pixel data, or null if it is not possible to create such an image.
    • decodeRaw

      public abstract void decodeRaw(byte[] b, int dstOffset, int bitsPerPixel, int scanlineStride) throws IOException
      Decodes the source data into the provided byte array b, starting at the offset given by dstOffset. Each pixel occupies bitsPerPixel bits, with no padding between pixels. Scanlines are separated by scanlineStride bytes.
      Parameters:
      b - a byte array to be written.
      dstOffset - the starting offset in b to be written.
      bitsPerPixel - the number of bits for each pixel.
      scanlineStride - the number of bytes to advance between that starting pixels of each scanline.
      Throws:
      IOException - if an error occurs reading from the source ImageInputStream.
    • decodeRaw

      public void decodeRaw(short[] s, int dstOffset, int bitsPerPixel, int scanlineStride) throws IOException
      Decodes the source data into the provided short array s, starting at the offset given by dstOffset. Each pixel occupies bitsPerPixel bits, with no padding between pixels. Scanlines are separated by scanlineStride shorts

      The default implementation calls decodeRaw(byte[] b, ...) and copies the resulting data into s.

      Parameters:
      s - a short array to be written.
      dstOffset - the starting offset in s to be written.
      bitsPerPixel - the number of bits for each pixel.
      scanlineStride - the number of shorts to advance between that starting pixels of each scanline.
      Throws:
      IOException - if an error occurs reading from the source ImageInputStream.
    • decodeRaw

      public void decodeRaw(int[] i, int dstOffset, int bitsPerPixel, int scanlineStride) throws IOException
      Decodes the source data into the provided int array i, starting at the offset given by dstOffset. Each pixel occupies bitsPerPixel bits, with no padding between pixels. Scanlines are separated by scanlineStride ints.

      The default implementation calls decodeRaw(byte[] b, ...) and copies the resulting data into i.

      Parameters:
      i - an int array to be written.
      dstOffset - the starting offset in i to be written.
      bitsPerPixel - the number of bits for each pixel.
      scanlineStride - the number of ints to advance between that starting pixels of each scanline.
      Throws:
      IOException - if an error occurs reading from the source ImageInputStream.
    • decodeRaw

      public void decodeRaw(float[] f, int dstOffset, int bitsPerPixel, int scanlineStride) throws IOException
      Decodes the source data into the provided float array f, starting at the offset given by dstOffset. Each pixel occupies bitsPerPixel bits, with no padding between pixels. Scanlines are separated by scanlineStride floats.

      The default implementation calls decodeRaw(byte[] b, ...) and copies the resulting data into f.

      Parameters:
      f - a float array to be written.
      dstOffset - the starting offset in f to be written.
      bitsPerPixel - the number of bits for each pixel.
      scanlineStride - the number of floats to advance between that starting pixels of each scanline.
      Throws:
      IOException - if an error occurs reading from the source ImageInputStream.
    • beginDecoding

      public void beginDecoding()
      This routine is called prior to a sequence of calls to the decode method, in order to allow any necessary tables or other structures to be initialized based on metadata values. This routine is guaranteed to be called any time the metadata values have changed.

      The default implementation computes tables used by the decode method to rescale components to different bit depths. Thus, if this method is overridden, it is important for the subclass method to call super(), unless it overrides decode as well.

    • decode

      public void decode() throws IOException
      Decodes the input bit stream (located in the ImageInputStream stream, at offset offset, and continuing for byteCount bytes) into the output BufferedImage image.

      The default implementation analyzes the destination image to determine if it is suitable as the destination for the decodeRaw method. If not, a suitable image is created. Next, decodeRaw is called to perform the actual decoding, and the results are copied into the destination image if necessary. Subsampling and offsetting are performed automatically.

      The precise responsibilities of this routine are as follows. The input bit stream is defined by the instance variables stream, offset, and byteCount. These bits contain the data for the region of the source image defined by srcMinX, srcMinY, srcWidth, and srcHeight.

      The source data is required to be subsampling, starting at the sourceXOffsetth column and including every subsampleXth pixel thereafter (and similarly for sourceYOffset and subsampleY).

      Pixels are copied into the destination with an addition shift of (dstXOffset, dstYOffset). The complete set of formulas relating the source and destination coordinate spaces are:

       dx = (sx - sourceXOffset)/subsampleX + dstXOffset;
       dy = (sy - sourceYOffset)/subsampleY + dstYOffset; 
       
      Only source pixels such that (sx - sourceXOffset) % subsampleX == 0 and (sy - sourceYOffset) % subsampleY == 0 are copied.

      The inverse mapping, from destination to source coordinates, is one-to-one:

       sx = (dx - dstXOffset)*subsampleX + sourceXOffset;
       sy = (dy - dstYOffset)*subsampleY + sourceYOffset;
       

      The region of the destination image to be updated is given by the instance variables dstMinX, dstMinY, dstWidth, and dstHeight.

      It is possible that not all of the source data being read will contribute to the destination image. For example, the destination offsets could be set such that some of the source pixels land outside of the bounds of the image. As a convenience, the bounds of the active source region (that is, the region of the strip or tile being read that actually contributes to the destination image, taking clipping into account) are available as activeSrcMinX, activeSrcMinY, activeSrcWidth and activeSrcHeight. Thus, the source pixel at (activeSrcMinX, activeSrcMinY) will map to the destination pixel (dstMinX, dstMinY).

      The sequence of source bands given by sourceBands are to be copied into the sequence of bands in the destination given by destinationBands.

      Some standard tag information is provided the instance variables photometricInterpretation, compression, samplesPerPixel, bitsPerSample, sampleFormat, extraSamples, and colorMap.

      In practice, unless there is a significant performance advantage to be gained by overriding this routine, most users will prefer to use the default implementation of this routine, and instead override the decodeRaw and/or getRawImageType methods.

      Throws:
      IOException - if an error occurs in decodeRaw.