François: When you say "Mega-Images (-> geo-sized images)", just how big are you talking about?
If you are in the 10-100GB range, I/LizardTech would be very interested in talking with you about the project, and also about supporting some of the geo metadata conventions. (Especially if you can do GB-sized data sets in less than 1GB of RAM without requiring the image be tiled!) ((Do you have any benchmark data you can share?) -mpg > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > François-Olivier Devaux > Sent: Tuesday, February 26, 2008 12:47 AM > To: discuss@lists.osgeo.org > Subject: [OSGeo-Discuss] 'lossless' JPEG2000 > > Hi, > > Norman Vine has pointed to me this discussion about JPEG 2000, and I > thought it might be interesting to give you a small overview on JPEG > 2000 and present the OpenJPEG library on which we are working. > > -------- > FIELDS WHERE JPEG 2000 IS USED > > JPEG 2000 is becoming the reference in image compression for > professional applications, where precision and flexibility is really > necessary. > > The most know field using JPEG 2000 is Digital Cinema, where > JPEG 2000 > has been favored against MPEG2 and H.264. Linked to that field, High > Quality Broadcast applications are also turning to JPEG 2000 > because of > its quality and scalability (low resolution versions can be extracted > directly from a high resolution sequence without any re-encoding, and > JPEG 2000 sequences are encoded in intra which eases video editing). > > More close to your field is Archiving, where we are feeling a > trend to > select JPEG 2000 as compression algorithm > http://www.egov.vic.gov.au/index.php?env=-inlink/detail:m1780- 1-1-8-s-0:l-9669-1-1-- > > Medical imaging applications, where lossless compression is a > important > requirement, are also taking full advantage of JPEG 2000 > remote browsing > possibilities (with the JPIP protocol) > http://www.earthtimes.org/articles/show/aware-inc-to-demonstra te-groundbreaking-medical-imaging-streaming-solution-at-> himss08,290686.shtml > > --------- > JPEG 2000 FEATURES > > The JPEG 2000 features that are interesting for GeoSpatial > Imagery is of > course the ability to achieve lossless compression, the scalability > (lower quality and resolutions as well as spatial areas can > be extracted > from a compressed file, without the need of decompression the entire > file), the high precision (most codecs can at least handle 16 > bits per > component, and up to 256 components) and the fact that the > core coding > system can be obtained free of charge. > JPEG 2000 also has an inherent robustness higher than most > compression > schemes (JPEG, ...) and a great protocol to interactively remotely > browse images called JPIP. > > ----- > OPENJPEG > > OpenJPEG, is an open-source JPEG 2000 library. It has been > very recently > remodeled by the CNES and the french company CS to meet the > requirements > of applications using Mega-Images (-> geo-sized images). Independent > access to tiles has been improved, in order to increase the library > encoding and decoding performances. This new version should be made > accessible to users at the beginning of March. We are very > happy of the > performances of this new version, and are open to new contributions. > Regarding other JPEG 2000 open source solutions in your > field, the GDAL > library has a JPEG 2000 module that is based on Jasper, which > is a great > library, but has unfortunately not evolved for the last years. > > ------------- > > Cheers, > > François > _______________________________________________ > Discuss mailing list > Discuss@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/discuss > _______________________________________________ Discuss mailing list Discuss@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/discuss