Class XTIFFTileCodecImpl

java.lang.Object
org.libtiff.jai.codec.XTIFFTileCodecImpl
All Implemented Interfaces:
XTIFFTileCodec
Direct Known Subclasses:
XTIFFFaxTileCodec, XTIFFLZWTileCodec, XTIFFPackTileCodec, XTIFFUncompTileCodec
public abstract class XTIFFTileCodecImpl extends Object implements XTIFFTileCodec
Provides a base class for writing TIFF tile codecs, to be registered with the XTIFFDirectory. This codec allows for both decoding and (optionally) encoding of tiles, and also handles the colorspace conversion in decoding.

At the minimum you will need to implement the two methods decodeTilePixels() for byte and short data, as well as the methods register() and create(). If your decoder requires additional parameters from the tags, set them up in initializeDecoding(), and initializeEncoding() for encoding.

To implement encoding, you must override the canEncode() method to return true, and implement encodeTilePixels().

Author:
Niles Ritter
See Also:

  • Field Details

    • directory

      protected XTIFFDirectory directory
      /////////////////////////////////////////////////// / Common Section ///////////////////////////////////////////////////

    • image

      protected RenderedImage image

    • minY

      protected int minY

    • minX

      protected int minX

    • width

      protected int width

    • length

      protected int length

    • numBands

      protected int numBands

    • tileLength

      protected int tileLength

    • tileWidth

      protected int tileWidth

    • compression

      protected int compression

    • sampleModel

      protected SampleModel sampleModel

    • sampleSize

      protected int[] sampleSize

    • bitsPerSample

      protected char[] bitsPerSample

    • colormap

      protected char[] colormap

    • encodeParam

      protected XTIFFEncodeParam encodeParam
      /////////////////////////////////////////////////// / Encoding Section ///////////////////////////////////////////////////

    • isTiled

      protected boolean isTiled

    • decodeParam

      protected XTIFFDecodeParam decodeParam
      /////////////////////////////////////////////////// / Decoding Section ///////////////////////////////////////////////////

    • decodePaletteAsShorts

      protected boolean decodePaletteAsShorts

    • unitsInThisTile

      protected int unitsInThisTile

    • _bdata

      protected byte[] _bdata

    • _sdata

      protected short[] _sdata

    • bpixvals

      protected byte[] bpixvals

    • spixvals

      protected short[] spixvals

    • buffer

      protected DataBuffer buffer

    • dataType

      protected int dataType

    • image_type

      protected int image_type

  • Constructor Details

    • XTIFFTileCodecImpl

      public XTIFFTileCodecImpl()
      The empty constructor.

  • Method Details

    • register

      public abstract void register()
      Registration method. Must be implemented by the extended class to register itself with the XTIFFDirectory for all compression codes it supports (e.g Fax codec supports 3 codes).
      Specified by:
      register in interface XTIFFTileCodec
      See Also:

    • create

      public abstract XTIFFTileCodec create()
      Implement this to return the corresponding empty codec object.

    • canEncode

      public boolean canEncode()
      Indicate whether this codec can encode data. Override to return true only if your codec implments encoding.

    • initializeDecoding

      public void initializeDecoding()
      The initialization method particular to decoding. Extend for whatever compression-specific information or parameters is needed. The decoding parameter has already been assigned at this point, as well as the XTIFFDirectory parsed from the input stream, and so all XTIFFFields are available.

    • initializeEncoding

      public void initializeEncoding()
      The initialization method particular to encoding. Extend for whatever compression-specific information or parameters is needed. The decoding parameter has already been assigned at this point, as well as the XTIFFDirectory parsed from the input stream, and so all XTIFFFields are available.

    • decodeTilePixels

      public abstract void decodeTilePixels(byte[] bpixels, Rectangle rect, byte[] pixels)
      decode bpixel byte array of data into pixels, packed for 1,2,4 8 bit pixels. Must implment this.
      Parameters:
      bpixels - the byte array of compressed input data
      rect - the rectangular shape of the target pixels
      pixels - the target decompressed pixels.

    • decodeTilePixels

      public abstract void decodeTilePixels(byte[] bpixels, Rectangle rect, short[] pixels)
      decode bpixel byte array of data into pixels, packed for 16 bit pixels. Must implment this.
      Parameters:
      bpixels - the byte array of compressed input data
      rect - the rectangular shape of the target pixels
      pixels - the target decompressed pixels.

    • encodeTilePixels

      public int encodeTilePixels(int[] pixels, Rectangle rect, byte[] bpixels)
      encode the tile in pixels into bpixels and return the byte size of the compressed data. Override this method if canEncode() = true;
      Parameters:
      pixels - input pixels
      rect - the array dimensions of samples
      bpixels - the target array of compressed byte data

    • initialize

      public void initialize()
      The method for initializing information common to both encoder and decoder.

    • getLongField

      protected long getLongField(int fld)
      A common utility method for accessing the XTIFFFields in the current image directory.

    • register

      public void register(int comp)
      This method may be used by the implementations register() method to register itself with the XTIFFDirectory.
      See Also:

    • setupSourceImage

      protected void setupSourceImage(RenderedImage img)
      One-time common image parameter setup
      Parameters:
      img - the source image that will be encoded into a TIFF formatted stream, or the TIFF image from which Raster tiles will be decoded.

    • getCompression

      public int getCompression()
      Returns the TIFF compression type
      Specified by:
      getCompression in interface XTIFFTileCodec

    • create

      public XTIFFTileCodec create(XTIFFEncodeParam param) throws IOException
      The method for creating an encoder from the XTIFFEncodeParam information.
      Specified by:
      create in interface XTIFFTileCodec
      Parameters:
      param - the encoding parameter. It is the responsibility of the codec to initialize itself from this parameter.
      Throws:
      IOException

    • initialize

      protected void initialize(XTIFFEncodeParam param) throws IOException
      Throws:
      IOException

    • encode

      public int encode(RenderedImage img, Rectangle rect, byte[] bpixels)
      Encode the data into buffer and return byte count Normally you will not need to override this method, but instead implement the encodeTilePixels() method.
      Specified by:
      encode in interface XTIFFTileCodec

    • setupBufferForEncoding

      protected void setupBufferForEncoding()
      One-time setup for encoding

    • getTilePixels

      protected void getTilePixels(Rectangle rect)
      Get the portion of tile fitting into buffer. You probably won't need to override this.
      Parameters:
      rect - the region to extract from image.

    • getCompressedTileSize

      public int getCompressedTileSize(RenderedImage im)
      If derived classes can make a better estimate for the maximum size of a compressed tile, they should override this, which assumes conservatively that it won't be worse than twice the original size.
      Specified by:
      getCompressedTileSize in interface XTIFFTileCodec
      Parameters:
      im - the rendered image containing the image data

    • create

      public XTIFFTileCodec create(XTIFFDecodeParam param) throws IOException
      The standard decoder creation method
      Specified by:
      create in interface XTIFFTileCodec
      Parameters:
      param - the decoding parameter. It is the responsibility of the codec to initialize itself from this parameter.
      Throws:
      IOException

    • initialize

      protected void initialize(XTIFFDecodeParam param) throws IOException
      Throws:
      IOException

    • setupBufferForDecoding

      protected void setupBufferForDecoding()
      One-time setup for encoding. Some configurations require a temp array for unpacking 16-bit palette data.

    • decode

      public WritableRaster decode(RenderedImage img, Rectangle newRect, byte[] bpixels)
      Decode a rectangle of data stored in bpixels into a raster tile. Usually you will not need to override this, but instead implement the decodeTilePixels methods.
      Specified by:
      decode in interface XTIFFTileCodec

    • decodeColor

      protected void decodeColor(Rectangle newRect)
      Postprocess the uncompressed color data into the appropriate display color model. This implementation Does a number of things:
      • For RGB color, reverse to BGR which apparently is faster for Java 2D display
      • For one-bit WHITE_IS_ZERO data, flip the values so that they will look correct
      • If the decodePaletteAsShorts flag is true then unpack the bits and apply the lookup table, as 16-bit lookup is not supported in JAI.
      Override this if you have other color types.
      See Also:

    • decodeTilePixels

      protected void decodeTilePixels(byte[] bpixels, Rectangle newRect)
      Decode a tile of data into either byte or short pixel buffers. Override this if you have other buffer types (e.g. int)

    • setTilePixels

      protected WritableRaster setTilePixels(Rectangle rect)
      Take the values from the buffer and store them in a WritableRaster object.

    • unpackShorts

      protected void unpackShorts(byte[] byteArray, short[] output, int shortCount)
      A useful Method to interpret a byte array as shorts. Method depends on whether the bytes are stored in a big endian or little endian format.

    • decodeColor

      protected void decodeColor(byte[] bpix, short[] sdata, Rectangle newRect)
      Decode short pixel data, or interpret palette data as short from byte.

    • decodeColor

      protected void decodeColor(short[] spix, short[] sdata, Rectangle newRect)
      Decode short color data, or interpret palette data as short.

    • decodeColor

      protected void decodeColor(byte[] bpix, byte[] bdata, Rectangle newRect)
      Decode byte color data