[gdal-dev] JP2 files created with JP2OpenJPEG can only have 1 or 3 bands?

[Even Rouault]

Le mercredi 15 octobre 2014 22:03:32, Paul Hasenohr a écrit :
> Hello Even,
> 
> Thank you for your answer.
> 
> In fact in my case, this 4th band is for a Near Infra Red channel so I
> definitely do not want to have it labelled as alpha!
> But I will have other satellite images with more than 4 bands (plus
> possibly an alpha band). Would it be possible to simply remove this
> check on the number of bands in CreateCopy()?

Yes, that should be possible. Please file a ticket in Trac about that.

> 
> Thanks,
> Paul
> 
> On 15/10/14 21:48, Even Rouault wrote:
> > Le mercredi 15 octobre 2014 21:19:37, Paul Hasenohr a écrit :
> >> Hello,
> >> 
> >> I just compiled gdal-1.11.1 with support for jpeg2000 through OpenJPEG
> >> and wanted to convert a 4 bands TIFF file (with LZW compression) into a
> >> lossless JP2 file.
> >> While attempting to run gdal_translate, I received this error message
> >> ERROR 6: Unable to export files with 4 bands
> >> 
> >> Looking at the file openjpegdataset.cpp [1], it seems that CreateCopy()
> >> only supports 1 band and 3 bands files. The option for 4 bands is even
> >> commented out. What is the reason for this?
> >> Would it be possible to support the creation of JPEG2000 of any number
> >> of bands?
> >> Can I safely enable the creation of 4 bands files?
> > 
> > I tested that recently and it mostly works except that the alpha band is
> > not correctly declared as alpha band, so other JPEG2000 codecs will see
> > it as a "unknown" band. I couldn't find in the openjpeg API how to
> > declare an alpha band. This would likely involved writing the
> > appropriate information in a JP2 box.
> > 
> >> I want to create GMLJP2 files as it is one option suggested by the
> >> INSPIRE technical guidelines on orthoimagery and I would like to use
> >> GDAL for this.
> >> 
> >> Thank you for your support.
> >> 
> >> Best regards,
> >> Paul Hasenohr
> >> 
> >> [1]
> >> https://svn.osgeo.org/gdal/trunk/gdal/frmts/openjpeg/openjpegdataset.cpp
> >> _______________________________________________
> >> gdal-dev mailing list
> >> gdal-dev at lists.osgeo.org
> >> http://lists.osgeo.org/mailman/listinfo/gdal-dev

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