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

[Nicholas G Lawrence]

I'm curious, why is OpenJpeg not compiled into GDAL by default? Is this a policy?

Thanks,
Nick

From: gdal-dev [mailto:gdal-dev-bounces at lists.osgeo.org] On Behalf Of Even Rouault
Sent: Tuesday, 29 August 2017 7:37 PM
To: gdal-dev at lists.osgeo.org
Cc: jratike80 <jukka.rahkonen at maanmittauslaitos.fi>
Subject: Re: [gdal-dev] Fwd: [OpenJPEG] OpenJPEG 2.2.0 is out ! Faster and safer.


On mardi 29 août 2017 01:42:21 CEST jratike80 wrote:

> N. Farah wrote

>

> > The results you get when enabling multi-threading are very interesting:

> > 26.s to 9.9 s. Then using the work in progress you end up with 1s.

> > Basically a 26 times speed improvement.

>

> Hi,

>

> As always when you read benchmarks, you must keep the results and the

> context together so it is clear what was tested. In this case the important

> part is that the test applies to single tiled images. They are what Kakadu

> prefers (also in the usage examples) and it handles them splendidly by

> utilizing the precincts. OpenJPEG has not been able to use precincts

> (despite in a fork

> https://lists.osgeo.org/pipermail/gdal-dev/2016-February/043650.html) and

> therefore it has slow with single tiled images and actually useless if the

> tile size is something like 20000 by 20000 pixels.

>

> Even can say how much faster the new branch is with JPEG2000 images which

> use 1024x1024 tiles but I suppose that the speed-up factor is much less than

> 26.



For tiled images, the GDAL OpenJPEG driver currently still read whole tiles (perhaps this should be re-considered at some point), so sub-tile decoding improvements will not help here, and you won't get more than the improvements done during 2.2.0, so something like 20% for openjpeg single-threaded (your mileage may vary), or more if you enable OPJ_NUM_THREADS.



Even



--

Spatialys - Geospatial professional services

http://www.spatialys.com


***********************************************************************
WARNING: This email (including any attachments) may contain legally
privileged, confidential or private information and may be protected by
copyright. You may only use it if you are the person(s) it was
intended to be sent to and if you use it in an authorised way. No one
is allowed to use, review, alter, transmit, disclose, distribute, print
or copy this email without appropriate authority.

If this email was not intended for you and was sent to you by mistake,
please telephone or email me immediately, destroy any hardcopies of
this email and delete it and any copies of it from your computer
system. Any right which the sender may have under copyright law, and 
any legal privilege and confidentiality attached to this email is not
waived or destroyed by that mistake.

It is your responsibility to ensure that this email does not contain 
and is not affected by computer viruses, defects or interference by 
third parties or replication problems (including incompatibility with
your computer system).

Opinions contained in this email do not necessarily reflect the
opinions of the Department of Transport and Main Roads,
or endorsed organisations utilising the same infrastructure.
***********************************************************************

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/gdal-dev/attachments/20170830/42681eef/attachment.html>