[OSGeo-Discuss] 'lossless' JPEG2000

[Christopher Schmidt]

On Mon, Feb 25, 2008 at 04:31:34PM -0800, Michael P. Gerlek wrote:
> Yup: Kakadu is not Open Source, as per the OSI definition of the term.
> The only FOSS package I know of is OpenJpeg2000 (or something like
> that); unfortunately, however, it is not suitable for geo-sized imagery
> last time I looked.

Yep.

> (LZW tiffs are a reasonable option, as they are lossless and the LZW
> patent issues have faded into the sunset.)

The level of compression from LZW is poor by comparison, on aerial
imagery: a test dataset compressed from 169MB to 83MB, and time to serve
up a small portion was approximately the same as with JPG (6.1s jpg,
6.5s lzw, .5s uncompressed), but the JPG was compressed to 13MB, making
it worth the cost; lzw doesn't pay for itself in the same way.

(See numbers on http://wiki.openaerialmap.org/Serving_Data)

Regards,
-- 
Christopher Schmidt
Web Developer