On Friday 07 August 2015 11:17:56 Jukka Rahkonen wrote: > ewenger <ewenger <at> ara.com> writes: > > I'm building GDAL 2.0 with JPEG-2000 support for my current project and I > > was surprised about the performance differences I saw between JasPer and > > OpenJPEG. Using JasPer, gdal_translate is able to decompress a 465 MB > > NITF C8 file in 2.3 minutes (wall clock) even though JasPer runs > > single-threaded. OpenJPEG took 4.4 minutes (wall clock) and used 24.5 > > minutes in CPU time across the four threads that were spawned. Is there > > some trick to building OpenJPEG that I'm not following or has anyone > > tried to multithread JasPer? > Hi, > > Could you point us any similar sample image for testing? > > Based on your timings both drivers are actually unusable for any real work > with your images. OpenJPEG is usually rather fast and much better than > JasPer but it can't handle any bigger images which are compressed into > JPEG2000 as one tile. NITF requires either that the tile size must not be > bigger that 1024x1024, or that the whole file is written as one single tile.
> I believe you have such single-tile NITF file. I'm not sure of this, since the multi-threaded decoding of the OpenJPEG driver can only be triggered with multiple JPEG2000 tiles. I've created a test 4096x4096 C8 NITF 3 bands with 1024x1024 tiles With that, gdal_translate to GTiff takes : - 2.5s with Jasper - 2.1s with OpenJPEG single threaded - 1.2s with OpenJPEG 4 threads Eric, are you sure you have built openjpeg in release mode ? > > -Jukka Rahkonen- > > > > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
