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

N. Farah nfarah at hotmail.com
Mon Aug 28 11:00:03 PDT 2017


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 ?


The two dataset i used:

<http://data.opengee.org/FusionTutorial-Full.tar.gz>

https://1drv.ms/u/s!AkFDoDHsFe7_hkBS6GbG4xMqnk6t<http://data.opengee.org/FusionTutorial-Full.tar.gz>
https://1drv.ms/u/s!AkFDoDHsFe7_hkG1-XDo7UztsPoC<http://data.opengee.org/FusionTutorial-Full.tar.gz>

p.s: i'm using GDAL 2.1.2


Noureddine

________________________________
From: Even Rouault <even.rouault at spatialys.com>
Sent: Monday, August 28, 2017 1:40:31 PM
To: N. Farah
Cc: gdal-dev at lists.osgeo.org
Subject: Re: [gdal-dev] Fwd: [OpenJPEG] OpenJPEG 2.2.0 is out ! Faster and safer.


Hi,



>

>

> I rebuilt GDAL (older version: 2.1.2) using this new open jpeg 2.2.0

> (https://github.com/uclouvain/openjpeg/releases/download/v2.2.0/openjpeg-v2

> .2.0-linux-x86_64.tar.gz)

>

> and tried to convert two jp2 dataset to tiff (gdal_translate):

>

> - bluemarble_4km.jp2: (10800 x 5400 pixels). 37.3 mb file size.

>

> - usgsLanSat.jp2: (8627 x 7745 pixels). 48 mb file size.



Do you know if they use JPEG2000 tiling ?



>

>

> Tests were run on virtual machine with ‘Ubuntu 16.04’ operation system, 18

> gb RAM and 2 CPU processors.

>



>

> These results were not expected since the new openJpeg should be faster than

> the previous one. Could this be cause by 'gdal_translate' not using threads

> that the new openjpeg uses for performance boost ?



By default, GDAL will now enable openjpeg thread support. So you need to set the OPJ_NUM_THREADS environment variable. That said, you should already get significant performance improvements even without enabling multi-threading. I'm not sure why you don't get them.



I'd be interested if you could share those images.



Even





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