[Gdal-dev] GML headers for JPEG2000 files

[Armin Burger]

Frank,

thanks for the quick reply. I would be mainly interested in the coordinate and georeference info in the Jp2 files. But of course, if other metadata could be added then the better.

At work we are currently using ER Mapper to convert files to ECW but are thinking to move to Jp2 because of better and standardized support of metadata. But the ER Mapper converter is not really transparent how to specify metadata, currently it seems to work just fine with a few standard projections like UTM. So we were thinking having a look at GDAL to use it instead.

How is the metadata defined in the CVS version of GDAL, via a separate file? Do you have any compiled version of the modified ECW SDK for Linux like the one from January? I was successful compiling the SDK but then could not compile GDAL with that one. It worked fine though with your pre-compiled version from January.

Best regards

Armin



> On 5/17/05, Armin Burger <armin.burger at gmx.net> wrote:
>> Hi Frank,
>>
>> I have a question regarding the new ECW SDK and JPEG2000 in GDAL:
>>
>> JPEG2000 supports metadata in GML format. Are there any plans to implement
>> this metadata headers in GDAL? Eg, when converting from a GeoTiff with
>> correct headers or defining the metadata in an XML file, writing the
>> corresponding metadata into the JPEG2000 file ?

> Armin,

> Currently GDAL CVS does support writing GML boxes per the
> evolving GML-in-JPEG2000 spec being worked on in the OGC
> GMLJP2 IE (interoperability experiment).   However, to do this
> it requires a patched version of the ECW SDK with support for
> some extra jp2 boxes.

> On reading the ECW driver supports reading these GML boxes,
> even with standard ECW SDKs as the gml reading code is all
> handled via the gdaljp2 modules in gdal/gcore.  I plan to extend
> use of this to the JP2KAK and possibly other jpeg2000 drivers in
> the future.

> However, you asked about metadata in GML.  Currently my work
> is only addressing coordinate system and georeferencing information
> in GML.  It is also quite practical to embed generic metadata in these
> gml packages, and I would like to do that.  I hadn't been pressing that
> issue though since we (in the gmljp2 ie) were finding general CRS
> work quite a challenge on it's own.

> So, I suppose you could say there is a general intention to implement
> generic metadata via gml in jpeg2000 files, but no fixed schedule for
> this.   It shouldn't be hard to do if you have a pressing need though.

> Best regards,
> --
> ---------------------------------------+------------------------------------
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> I set the clouds in motion - turn up   | Frank Warmerdam,
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