[OSGeo-Discuss] 'lossless' JPEG2000

[François-Olivier Devaux]

Hi Michael,

We made some tests with tiles of 1000*1000 pixels, with 10000 tiles, and 
the memory used is about 112 MB for the encoding and 114 MB for the 
decoding.
If you don't want to use tiles, I don't think OpenJPEG can beat the 
commercial applications like Kakadu.

What standard do you follow for metadata ? OGC GMLJP2, or do you include 
GeoTIFF information in a JP2 file like Luratech suggested to the JPEG 
committee ?

Cheers,

François

Michael P. Gerlek a écrit :
> 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: discuss-bounces at lists.osgeo.org 
>> [mailto:discuss-bounces at lists.osgeo.org] On Behalf Of 
>> François-Olivier Devaux
>> Sent: Tuesday, February 26, 2008 12:47 AM
>> To: discuss at 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
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>>
>>     
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