JIU 0.14.3

net.sourceforge.jiu.codecs.tiff
Class TIFFDecoder

java.lang.Object
  extended by net.sourceforge.jiu.codecs.tiff.TIFFDecoder
Direct Known Subclasses:
TIFFDecoderDeflated, TIFFDecoderLogLuv, TIFFDecoderModifiedHuffman, TIFFDecoderPackbits, TIFFDecoderUncompressed

public abstract class TIFFDecoder
extends Object

The abstract base class for a TIFF decoder, a class that decompresses one tile or strip of image data and understands one or more compression types. Each child class implements the decoding of a particular TIFF compression type in its decode() method.

This class does all the work of storing decompressed data (given as a byte array) in the image object. Given the many variants (sample order, color depth, color space etc.) this is a larger portion of code.

Since:
0.7.0
Author:
Marco Schmidt

Constructor Summary
TIFFDecoder()
           
 
Method Summary
abstract  void decode()
          Decode data from input and write the decompressed pixel data to the image associated with this decoder.
 int getBytesPerRow()
          Returns the number of bytes per row for the strip or tile that this decoder deals with.
 TIFFCodec getCodec()
          Returns the codec from which this decoder is used.
abstract  Integer[] getCompressionTypes()
          Returns an array with Integer values of all compression types supported by this decoder (see the COMPRESSION_xyz constants in TIFFConstants.
 TIFFImageFileDirectory getImageFileDirectory()
          Returns the IFD for the image this decoder is supposed to uncompress (partially).
 DataInput getInput()
          Returns the input stream from which this decoder is supposed to read data.
 int getTileIndex()
          Returns the zero-based index of the tile or strip this decoder is supposed to be decompressing.
 int getX1()
          Returns the leftmost column of the image strip / tile to be read by this decoder.
 int getX2()
          Returns the rightmost column of the image strip / tile to be read by this decoder.
 int getY1()
          Returns the top row of the image strip / tile to be read by this decoder.
 int getY2()
          Returns the bottom row of the image strip / tile to be read by this decoder.
 void initialize()
          Check if all necessary parameters have been given to this decoder and initialize several internal fields from them.
 void putBytes(byte[] data, int offset, int number)
          Adds a number of bytes to the internal row buffer.
 void setCodec(TIFFCodec tiffCodec)
          Specify the codec to be used with this decoder.
 void setImageFileDirectory(TIFFImageFileDirectory tiffIfd)
          Specify the IFD to be used with this decoder.
 void setTileIndex(int index)
          Specify the zero-based tile index for the tile or strip to be decompressed by this decoder.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

TIFFDecoder

public TIFFDecoder()
Method Detail

decode

public abstract void decode()
                     throws InvalidFileStructureException,
                            IOException
Decode data from input and write the decompressed pixel data to the image associated with this decoder. Child classes must override this method to implement the decoding for a particular compression type.

Throws:
InvalidFileStructureException
IOException

getBytesPerRow

public int getBytesPerRow()
Returns the number of bytes per row for the strip or tile that this decoder deals with. So with a tiled TIFF and an image width of 500 and a tile width of 100, for an eight bit grayscale image this would return 100 (not 500).

Returns:
number of bytes per row

getCodec

public TIFFCodec getCodec()
Returns the codec from which this decoder is used.

Returns:
TIFFCodec object using this decoder

getCompressionTypes

public abstract Integer[] getCompressionTypes()
Returns an array with Integer values of all compression types supported by this decoder (see the COMPRESSION_xyz constants in TIFFConstants. Normally, this is only one value, but some compression types got assigned more than one constant (e.g. deflated). Also, a decoder could be capable of dealing with more than one type of compression if the compression types are similar enough to justify that. However, typically a decoder can only deal with one type of compression.

Returns:
array with Integer objects of all TIFF compression constants supported by this decoder

getImageFileDirectory

public TIFFImageFileDirectory getImageFileDirectory()
Returns the IFD for the image this decoder is supposed to uncompress (partially).

Returns:
IFD object

getInput

public DataInput getInput()
Returns the input stream from which this decoder is supposed to read data.


getTileIndex

public int getTileIndex()
Returns the zero-based index of the tile or strip this decoder is supposed to be decompressing.

Returns:
tile index

getX1

public int getX1()
Returns the leftmost column of the image strip / tile to be read by this decoder.


getX2

public int getX2()
Returns the rightmost column of the image strip / tile to be read by this decoder.


getY1

public int getY1()
Returns the top row of the image strip / tile to be read by this decoder.


getY2

public int getY2()
Returns the bottom row of the image strip / tile to be read by this decoder.


initialize

public void initialize()
                throws IOException,
                       MissingParameterException
Check if all necessary parameters have been given to this decoder and initialize several internal fields from them. Required parameters are a TIFFCodec object, a TIFFImageFileDirectory object and a tile index.

Throws:
IOException
MissingParameterException

putBytes

public void putBytes(byte[] data,
                     int offset,
                     int number)
Adds a number of bytes to the internal row buffer. If the row buffer gets full (a complete line is available) that data will be copied to the image. Note that more than one line, exactly one line or only part of a line can be stored in the number bytes in data.

Parameters:
data - byte array with image data that has been decoded
offset - int index into data where the first byte to be stored is situated
number - int number of bytes to be stored

setCodec

public void setCodec(TIFFCodec tiffCodec)
Specify the codec to be used with this decoder. This is a mandatory parameter - without it, initialize() will throw an exception.

Parameters:
tiffCodec - TIFFCodec object to be used by this decoder
See Also:
getCodec()

setImageFileDirectory

public void setImageFileDirectory(TIFFImageFileDirectory tiffIfd)
Specify the IFD to be used with this decoder. This is a mandatory parameter - without it, initialize() will throw an exception.

Parameters:
tiffIfd - object to be used by this decoder
See Also:
getImageFileDirectory()

setTileIndex

public void setTileIndex(int index)
Specify the zero-based tile index for the tile or strip to be decompressed by this decoder. This is a mandatory parameter - without it, initialize() will throw an exception.

Parameters:
index - zero-based tile / strip index
See Also:
getTileIndex()

JIU 0.14.3

Copyright © 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Marco Schmidt