Digital BW, The Print

Hi,
Just a quick note about a free Photoshop plug-in that converts file 
into JPEG2000 format.

It has both a lossless and a lossy mode. In lossless mode it 
compressed a 55mb file into a 10mb .jp2 file. 

It's available at: 
http://www.fnordware.com/j2k/

Anyone knowns if it really offer lossless compression ?

Cheers
Andre