2005.09.23 22:20 "Re: [Tiff] Additional Lossless Compression Schemes", by Chris Cox

I was wondering if there is much interest in adding more lossless compression schemes in libtiff.

In addition to Packbits (pretty crappy) we have LZW and the more recent Deflate. My understanding is that Deflate is usually better than the old LZW though not as widely supported. Also, that Deflate is essentially the "zip" compression type.

Yes, yes, and yes.

Since then I have seen "gzip" on Unix, but I am not clear if that is just deflate or not.

Then came bzip2 which seem 5-10% better in that gzip on many datasets.

Since TIFF supports predictors, it can already do better than straight deflate.

Now looking around a bit I see LZMA which I have heard good things about.

   http://www.7-zip.org/sdk.html

Are there any opinions on possibly incorporating LZMA as an additional compression type?

Possibly - but it'll take a while to check the legal implications, get a couple of implementations going for cross testing, etc.

And I'd expect it to be at least 10% better than deflate to be worth the effort...

Chris