How can I do LZW decoding in Java?

Question

I have a database which contains picture data stored as a binary blob. The documentation says the data is encoded using LZW. I thought that I could decode it using the Zip o

Answer 1

I went through a surprising amount of LZW implementations before finding one that worked for my case.

UncompressedInputStream from the BioJava project worked for me, when I needed to unpack a .pax file.

Answer 2

I know the question is old, but I just wanted to add a great resource about LZW:

http://www.matthewflickinger.com/lab/whatsinagif/lzw_image_data.asp

It's more specifically about the use of LZW in GIF images, but it explains the compression and decompression algorithms pretty well.

Answer 3

You can also try with 7-Zip JBinding which uses the 7zip library internally. It's quite easy to use.

Answer 4

Here are a couple of links:

• http://www.cs.sfu.ca/CC/365/li/squeeze/LZW.html

• http://u.cs.biu.ac.il/~freskom1/AlgProg1/Progs/LZW.java

• http://www.codeproject.com/KB/java/lzw.aspx

And there are others.

Indeed if the images are LZW compressed TIFF files, The Java Advanced Imaging API apparently supports decoding directly (though not encoding it seems).