[gdal-dev] Is it a big thing to change ECW to support 16-bit imagery?

[Even Rouault]

Mo,

NITF driver cannot use Jasper for reading JPEG2000 compressed NITF images, 
because Jasper doesn't support decoding an image that is located at an 
arbitrary offset inside a file. (At least, that's the first reason why it 
can't work.). I imagine that if you badly want to use Japser, you could hack 
the NITF driver so that it writes a temporary image with just the JPEG200 
content and pass it to the Jasper driver.

Even

Le Saturday 28 March 2009 14:19:42 mohwawang, vous avez écrit :
> Ivan,
>
> It seems that both you and me guess that it is a big thing to change the
> source code of ECW SDK to support 16bit imagery.
>
> So, forget about ECW. How about another jpeg2000 package, Jasper, which
> (1)supports 8bit and 16bit and (2)is an open source. GDAL has a driver for
> Jasper jpeg2000. But GDAL does not allow NITF with Jasper. GDAL only allows
> NITF with ECW jpeg2000, which we know (1)does not support 16bit and (2)has
> license issue. Why GDAL does not support Jasper jpeg2000 in NITF?
>
> Best Regards,
>
> Mo
>
> --- On Sat, 3/28/09, Ivan Lucena <ivan.lucena at pmldnet.com> wrote:
> > From: Ivan Lucena <ivan.lucena at pmldnet.com>
> > Subject: Re: [gdal-dev] Is it a big thing to change ECW to support 16-bit
> > imagery? To: "mohwawang" <mohwawang at yahoo.com>
> > Cc: gdal-dev at lists.osgeo.org
> > Date: Saturday, March 28, 2009, 12:10 AM
> > Mo,
> >
> > See, GDAL does not implement the code that actually reads
> > the ECW format. The GDAL ECW driver just make calls to a
> > external library. That library is provided by the company
> > that holds the copyright for that format [1]. So you would
> > need to ask and negotiate with then first.
> >
> > But I believe that they probably have thought about that
> > before and maybe that *is* a "big thing", as you said. It is
> > not just a matter of storing pixels values but it is matter
> > of running a algorithm to calculate the wavelets. Or maybe
> > is just because that is how and why the format was designed.
> > I mean, for byte image.
> >
> > But if they *do* decided to implement that change I believe
> > it will be pretty simple for anyone of the GDAL driver's
> > developers to make the necessary changes to adapt to it.
> >
> > But like I said before, don't hold you breath waiting for
> > that. I don't think that there is a chance.
> >
> > [1] http://www.gdal.org/frmt_ecw.html
> >
> > My best regards,
> >
> > Ivan
> >
> > mohwawang wrote:
> > > Mateusz,
> > >
> > > License issue can be resolved through negotiation.
> >
> > Then back to the technique issue: Is it a big thing to
> > change ECW to support 16-bit imagery?
> >
> > > Mo 
> > > --- On Fri, 3/27/09, Mateusz Loskot <mateusz at loskot.net>
> >
> > wrote:
> > >> From: Mateusz Loskot <mateusz at loskot.net>
> > >> Subject: Re: [gdal-dev] Is it a big thing to
> >
> > change ECW to support 16-bit imagery?
> >
> > >> To: "mohwawang" <mohwawang at yahoo.com>
> > >> Cc: gdal-dev at lists.osgeo.org
> > >> Date: Friday, March 27, 2009, 7:31 PM
> > >>
> > >> mohwawang wrote:
> > >>> Mateuse,
> > >>>
> > >>> So what's the answer to the "correct"
> >
> > question?
> >
> > >> Read the license.
> > >>
> > >> Best regards,
> > >> -- Mateusz Loskot, http://mateusz.loskot.net
> > >> Charter Member of OSGeo, http://osgeo.org
> > >
> > >   
> >
> >    _______________________________________________
> >
> > > gdal-dev mailing list
> > > gdal-dev at lists.osgeo.org
> > > http://lists.osgeo.org/mailman/listinfo/gdal-dev
>
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