[OSGeo-Discuss] Open File Formats and Proprietary Algorithms
Michael P. Gerlek
mpg at lizardtech.com
Thu Aug 20 13:54:37 PDT 2009
- MrSID has both lossy and lossless modes
- MrSID is not fractal based; it uses wavelets (and arithmetic encoding)
- you can't copyright algorithms; the MrSID source code certainly is, however
- MrSID relies on a number of patents, not all of which are owned by LizardTech
- reading MrSID does not require any fees; we have libraries you can download, although they are not open source
That said, some editorial comments (although I'm now wishing I hadn't been so quick to rise to Landon's bait :-)
- Some of you know the history of trying to open source MrSID; I won't go into that here, except to say that LizardTech doesn't own all of the required IP needed to make that happen.
- If we are speaking of the NAIP data, then no, it is not exclusively available in MrSID format; it is also shipped as GeoTIFFs.
- JPEG 2000 is a very robust open standard alternative to MrSID, and a number of players already support it (including LizardTech), but not enough to make it viable for certain domains like NAIP.
- some of you also know the history on open JP2 support: there is today no open source implementation of JP2 that is suitable for geo work. Alas.
From: discuss-bounces at lists.osgeo.org [mailto:discuss-bounces at lists.osgeo.org] On Behalf Of Eric Wolf
Sent: Thursday, August 20, 2009 2:15 PM
To: OSGeo Discussions
Subject: Re: [OSGeo-Discuss] Open File Formats and Proprietary Algorithms
The MRSID format is a very special case - and perhaps an opportunity for a new FOSS file format. MRSID is a lossless, fractal-based, multi-scale raster compression format. LizardTech has the algorithms to encode and decode MRSID locked up in copyrights, and I believe, patents. Even companies like ESRI shell out big bucks to LizardTech to be able to read and write the MRSID format.
I guess I missed the context of the discussion. Is the government releasing certain data exclusively in this format? If so, I think the argument can be made against this practice. The different in compression between MRSID and gziped TIFFs isn't really that great in this day of cheap disks and fat pipes.
Eric B. Wolf New! 720-334-7734
Center of Excellence in GIScience
CU-Boulder - Geography
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