Package com.sun.pdfview.decode

Class LZWDecode

  • public class LZWDecode
extends java.lang.Object
    decode an LZW-encoded array of bytes. LZW is a patented algorithm.

    Feb 21, 2009 Legal statement on Intellectual Property from Unisys

     LZW Patent Information (http://www.unisys.com/about__unisys/lzw)
 License Information on GIF and Other LZW-based Technologies
 
    
 Unisys U.S. LZW Patent No. 4,558,302 expired on June 20, 2003,
 the counterpart patents in the United Kingdom, France, Germany and
 Italy expired on June 18, 2004, the Japanese counterpart patents
 expired on June 20, 2004 and the counterpart Canadian patent
 expired on July 7, 2004.
 
    
 Unisys Corporation holds and has patents pending on a number of
 improvements on the inventions claimed in the above-expired patents.
 Information on these improvement patents and terms under which they
 may be licensed can be obtained by contacting the following:

    
 Unisys Corporation
 Welch Patent Licensing Department
 Mail Stop E8-114
 Unisys Way
 Blue Bell, PA  19424

    
 Via the Internet, send email to Robert.Marley@unisys.com.

    
 Via facsimile, send inquiries to Welch Patent Licensing Department at
 215-986-3090.

    
 The above is presented for information purposes only, and is subject
 to change by Unisys.  Additionally, this information should not be
 considered as legally obligating Unisys in any way with regard to license
 availability, or as to the terms and conditions offered for a license,
 or with regard to the interpretation of any license agreements.
 You should consult with your own legal counsel regarding your
 particular situation.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) int bitpos  
      (package private) int bitspercode  
      (package private) java.nio.ByteBuffer buf  
      (package private) int bytepos  
      (package private) static int CLEARDICT  
      (package private) byte[][] dict  
      (package private) int dictlen  
      (package private) static int STOP  

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private LZWDecode​(java.nio.ByteBuffer buf)
      initialize this decoder with an array of encoded bytes

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private java.nio.ByteBuffer decode()
      decode the array.
      static java.nio.ByteBuffer decode​(java.nio.ByteBuffer buf, PDFObject params)
      decode an array of LZW-encoded bytes to a byte array.
      private int nextCode()
      get the next code from the input stream
      private void resetDict()
      reset the dictionary to the initial 258 entries

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • buf

        java.nio.ByteBuffer buf

      • bytepos

        int bytepos

      • bitpos

        int bitpos

      • dict

        byte[][] dict

      • dictlen

        int dictlen

      • bitspercode

        int bitspercode

      • STOP

        static int STOP

      • CLEARDICT

        static int CLEARDICT

    • Constructor Detail

      • LZWDecode

        private LZWDecode​(java.nio.ByteBuffer buf)
           throws PDFParseException
        initialize this decoder with an array of encoded bytes
        Parameters:
        buf - the buffer of bytes
        Throws:
        PDFParseException

    • Method Detail

      • resetDict

        private void resetDict()
        reset the dictionary to the initial 258 entries

      • nextCode

        private int nextCode()
        get the next code from the input stream

      • decode

        public static java.nio.ByteBuffer decode​(java.nio.ByteBuffer buf,
                                         PDFObject params)
                                  throws java.io.IOException
        decode an array of LZW-encoded bytes to a byte array.
        Parameters:
        buf - the buffer of encoded bytes
        params - parameters for the decoder (unused)
        Returns:
        the decoded uncompressed bytes
        Throws:
        java.io.IOException