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

[mohwawang]

Even,

Thank you for telling me the reason why GDAL does not support Jasper for reading a NITF file and how to hack that. How about writing (instead of reading) a Jasper compressed image into NITF?

I want to be able to write out not read in a JPG2000 compressed NITF file. (My input image is a 16bit raw image). Why GDAL does not support writing a Jasper compressed image into NITF? How to hack that? Thanks.

Mo

--- On Sat, 3/28/09, Even Rouault <even.rouault at mines-paris.org> wrote:

> From: Even Rouault <even.rouault at mines-paris.org>
> Subject: Re: [gdal-dev] Is it a big thing to change ECW to support 16-bit imagery?
> To: gdal-dev at lists.osgeo.org
> Cc: "mohwawang" <mohwawang at yahoo.com>
> Date: Saturday, March 28, 2009, 9:36 AM
> 
> -----Inline Attachment Follows-----
> 
> 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
> > > >
> > > >   
> > >
> > >
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