[gdal-dev] OpenJPEG Testers Needed

[Aaron Boxer]

On Wed, Jan 13, 2016 at 2:40 PM, Even Rouault <even.rouault at spatialys.com>
wrote:

>
> > So, are you saying there are actual pixel differences between encoded
> file
> > and original?
>
> Yes
>

I see. So, this is repeatable every time you run the test suite?  And you
can't reproduce
with opj_compress followed by opj_decompress ?


> > > oh, so how does one make a forward struct declaration to make gcc 4.4
> > happy ?
>
> Apparently it doesn't like to see "typedef struct foo { ... } bar"
> (openjpeg.h) and "typedef struct foo bar" (region_mgr.h).
> If openjpeg.h was "struct foo { ... }", that would work (but we cannot
> touch
> that one). Why not just including openjpeg.h in region_mgr.h to avoid the
> typedef redefinitions ?
>
>
Thanks, I moves some code around and now it should compile on 4.4.


> >
> > > Testing with 2048x2048 tiled images, with OpenMP enabled, I can see
> perf
> > > improvements.
> > > For example ~2s  (4 vCPU) vs ~3s (openjpeg 2.1) to decode a tile.
> > >
> > > Great. So, this is good. What are your system specs, may I ask ?
>
> Was on a i5 CPU 750 @ 2.67GHz, 4 GB RAM, 64bit build
>
> OK, thanks.


> > >
> > >
> > >
> > >
> > > With a single tiled 11310x17310 image with which GDAL uses the
> > > opj_set_decode_area() area,
> > > I couldn't really see the difference as the memory consumption grows to
> > > above 2 GB,
> > > which cause disk trashing on the system on which I test.
> >
> > Yes, that makes sense, there is still work to be done, I guess. The
> wavelet
> > transform
> > needs to be modified to be more memory efficient.  What size of decode
> area
> > would you
> > typically want to set on an image of that size ?
>
> One use case could be for displaying in a desktop GIS application (QGIS for
> example), so the size of the display area. Let's say 2000x1000 max.
>
>
Great, thanks for the feedback.




> >
> >
> > Thanks again,
> > Aaron
> >
> >
> > Even
> >
> > > --
> > > Spatialys - Geospatial professional services
> > > http://www.spatialys.com
>
> --
> Spatialys - Geospatial professional services
> http://www.spatialys.com
>
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