[gdal-dev] Fwd: [OpenJPEG] OpenJPEG 2.2.0 is out ! Faster and safer.

[Even Rouault]

On lundi 28 août 2017 18:00:03 CEST N. Farah wrote:
> Thanks Even for the quick response. I'll give it a try with setting
> OPJ_NUM_THREADS env variable to 8. Does it need to be used with
> GDAL_NUM_THREADS ? Any url to read about those two env variables ?
> 
> 

I've added some documentation per
https://trac.osgeo.org/gdal/changeset/39954


> The two dataset i used:
> 
> <http://data.opengee.org/FusionTutorial-Full.tar.gz>
> 
> https://1drv.ms/u/s!AkFDoDHsFe7_hkBS6GbG4xMqnk6t<http://data.opengee.org/Fus
> ionTutorial-Full.tar.gz>
> https://1drv.ms/u/s!AkFDoDHsFe7_hkG1-XDo7UztsPoC<http://data.opengee.org/Fu
> sionTutorial-Full.tar.gz>

Those images are single-tiled, so the GDAL_NUM_THREADS optimization will not help for 
them, and current openjpeg versions are super inefficient on those use cases, as GDAL 
expose a pseudo tiling to avoid a super big tile size, which cause the whole image to be 
decoded multiple times. I'm currently working on improving subtile decoding, that will 
substantially improve performance for such images (first steps are already in openjpeg 
master, next to follow)

I didn't have the patience to convert the whole image, so just took 3 GDAL blocks of 
1024x1024
Without threading support, on hot runs:

gdal_translate bluemarble_4km.jp2 out.tif -srcwin 0 0 3072 1024

35.1 s  GDAL 2.2 / openjpeg 2.1.2
26.2 s  GDAL 2.2 / openjpeg 2.2.0

So I do see an improvement. Not sure why you don't.

Hardware: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
OS: Ubuntu 16.04, 64bit build


and as a teaser:
3.1 s   GDAL 2.2 / openjpeg master
1.5 s   GDAL 2.2 / openjpeg (my work-in-progress branch)

With 8 threads:
9.9 s  GDAL 2.2 / openjpeg 2.2.0
2.3 s  GDAL 2.2 / openjpeg master
0.9 s  GDAL 2.2 / openjpeg (my work-in-progress branch)



With usgsLanSat.jp2

gdal_translate usgsLanSat.jp2 out.tif -srcwin 0 0 3072 1024

40.2 s  GDAL 2.2 / openjpeg 2.1.2
32.3 s  GDAL 2.2 / openjpeg 2.2.0

> 
> p.s: i'm using GDAL 2.1.2

GDAL 2.1 or 2.2 should have comparable performances on this, I think

-- 
Spatialys - Geospatial professional services
http://www.spatialys.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/gdal-dev/attachments/20170828/ebf0df0e/attachment.html>