Class TIFFCompressor

java.lang.Object
com.github.jaiimageio.plugins.tiff.TIFFCompressor
Direct Known Subclasses:
TIFFBaseJPEGCompressor, TIFFDeflater, TIFFFaxCompressor, TIFFLSBCompressor, TIFFLZWCompressor, TIFFNullCompressor, TIFFPackBitsCompressor

public abstract class TIFFCompressor extends Object
An abstract superclass for pluggable TIFF compressors.
  • Field Details

    • writer

      protected ImageWriter writer
      The ImageWriter calling this TIFFCompressor.
    • metadata

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

      protected String compressionType
      The name of the compression type supported by this compressor.
    • compressionTagValue

      protected int compressionTagValue
      The value to be assigned to the TIFF Compression tag in the TIFF image metadata.
    • isCompressionLossless

      protected boolean isCompressionLossless
      Whether the compression is lossless.
    • stream

      protected ImageOutputStream stream
      The ImageOutputStream to be written.
  • Constructor Details

    • TIFFCompressor

      public TIFFCompressor(String compressionType, int compressionTagValue, boolean isCompressionLossless)
      Creates a compressor object for use in compressing TIFF data. This object may be passed to the TIFFImageWriteParam.setTIFFCompressor(TIFFCompressor) method to override the compressor of a supported compression type or to provide the implementation of the compression algorithm of an unsupported compression type.

      The parameters compressionTagValue and isCompressionLossless are provided to accomodate compression types which are unknown. A compression type is "known" if it is either among those already supported by the TIFF writer (see TIFFImageWriteParam), or is listed in the TIFF 6.0 specification but not supported. If the compression type is unknown, the compressionTagValue and isCompressionLossless parameters are ignored.

      Parameters:
      compressionType - The name of the compression type.
      compressionTagValue - The value to be assigned to the TIFF Compression tag in the TIFF image metadata; ignored if compressionType is a known type.
      isCompressionLossless - Whether the compression is lossless; ignored if compressionType is a known type.
      Throws:
      IllegalArgumentException - if compressionType is null or compressionTagValue is less than 1.
  • Method Details

    • getCompressionType

      public String getCompressionType()
      Retrieve the name of the compression type supported by this compressor.
      Returns:
      The compression type name.
    • getCompressionTagValue

      public int getCompressionTagValue()
      Retrieve the value to be assigned to the TIFF Compression tag in the TIFF image metadata.
      Returns:
      The Compression tag value.
    • isCompressionLossless

      public boolean isCompressionLossless()
      Retrieves a value indicating whether the compression is lossless.
      Returns:
      Whether the compression is lossless.
    • setStream

      public void setStream(ImageOutputStream stream)
      Sets the ImageOutputStream to be written.
      Parameters:
      stream - an ImageOutputStream to be written.
      See Also:
    • getStream

      public ImageOutputStream getStream()
      Returns the ImageOutputStream that will be written.
      Returns:
      an ImageOutputStream.
      See Also:
    • setWriter

      public void setWriter(ImageWriter writer)
      Sets the value of the writer field.
      Parameters:
      writer - the current ImageWriter.
      See Also:
    • getWriter

      public ImageWriter getWriter()
      Returns the current ImageWriter.
      Returns:
      an ImageWriter.
      See Also:
    • setMetadata

      public void setMetadata(IIOMetadata metadata)
      Sets the value of the metadata field.
      Parameters:
      metadata - the IIOMetadata object for the image being written.
      See Also:
    • getMetadata

      public IIOMetadata getMetadata()
      Returns the current IIOMetadata object.
      Returns:
      the IIOMetadata object for the image being written.
      See Also:
    • encode

      public abstract int encode(byte[] b, int off, int width, int height, int[] bitsPerSample, int scanlineStride) throws IOException
      Encodes the supplied image data, writing to the currently set ImageOutputStream.
      Parameters:
      b - an array of bytes containing the packed but uncompressed image data.
      off - the starting offset of the data to be written in the array b.
      width - the width of the rectangle of pixels to be written.
      height - the height of the rectangle of pixels to be written.
      bitsPerSample - an array of ints indicting the number of bits used to represent each image sample within a pixel.
      scanlineStride - the number of bytes separating each row of the input data.
      Returns:
      the number of bytes written.
      Throws:
      IOException - if the supplied data cannot be encoded by this TIFFCompressor, or if any I/O error occurs during writing.
    • dispose

      public void dispose()
      Allows any resources held by this object to be released. The result of calling any other method (other than finalize) subsequent to a call to this method is undefined.

      It is important for applications to call this method when they know they will no longer be using this TIFFCompressor. Otherwise, the writer may continue to hold on to resources indefinitely.

      The default implementation of this method in the superclass does nothing. Subclass implementations should ensure that all resources, especially native resources, are released.