MapServer WCS - Jpeg2000

[Frank Warmerdam]

On Apr 5, 2005 12:18 PM, Norman Barker <nbarker at rsinc.com> wrote:
> Hi,
>
> been looking at the WCS impl again, with particular reference to NetCDF.
>
> A comment by Frank Warmerdam said any format that supported bands could be used,
> not necessarily geotiff.  Well compression in geotiff does nothing for NetCDF but
> JP2k had a compression ratio of 40% (obviously this changes due to quality levels etc.)
>
> This leads to some questions
>
> 1) The WMS supports JP2k, any reason why it should work with the WCS?

Norman,

JP2K should work fine with WCS - assuming your WCS client knows what to
do with the files.

> 2) JP2K over http doesn't give many advantages apart from disk storage size, are they
> any plans to implement jpip over http to give streaming capabilities?

This does not make sense in the MapServer context.  GDAL client support for
JPIP was incorporated some time ago but I could never get it to work very well.
I have no immediately plans to pursue that further.

> 3) Finally if anyone knows how to implement the temporal dimension in the WCS I would
> be grateful!!

Steve Lime has examples of this up somewhere.   Hopefully he'll follow up on
this.  But you might find info in the WCS  topic in the wiki.

> OpenGIS announced an initiative to put GML coverages inside Jpeg2000 which is interesting, but
> I just want to serve the data at the moment, and use the XML inside the Jpeg2000 to hold a scaling value
> since Jp2k can't hold floating points.

Getting the scaling value into the JP2K file will require some custom
work for you both on the server and the client.   I am interested in
carrying scale and offset values in GML coverages in J2K files but
haven't started to explore that.  I only just recently added support in
GDAL for reading and writing them in GeoTIFF (in a custom tag).  Even
with that done, it still doesn't kick in with MapServer since MapServer
doesn't try to copy that sort of metadata into the generated map.  Perhaps
we will eventually need OutputFormat options to attach extra metadata
to output files.

Best regards,
--
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent