[mapserver-users] Big CVS Update

[Jean-Francois.Doyon at ccrs.nrcan.gc.ca]

As a curiosity, will the PDF output be handled in the same way as well ?

J.F.

-----Original Message-----
From: Frank Warmerdam [mailto:warmerdam at pobox.com]
Sent: Tuesday, June 11, 2002 12:43 PM
To: UMN MapServer
Subject: Re: [mapserver-users] Big CVS Update


Brent Fraser wrote:
> Frank,
> 
>   I read your Wiki doc.  Looks good!
> 
> Any thoughts on JPEG2000 (especially wavelet) support and a FORMATOPTION
> relating to compression for geotiff?

Brent,

All GDAL file creation options can be applied via the FORMATOPTION keyword,
so this includes GDAL's capability to apply compression.  Last night I
tested
this by adding 'FORMATOPTION "COMPRESS=PACKBITS"' in a GeoTIFF OUTPUTFORMAT
definition and it worked fine.

I have looked at a JPEG 2000 library and would eventually like to
incorporate
it into GDAL at which point it would then also be supported by MapServer;
however, I haven't had any funding for such work.  Also, I believe the
JPEG 2000 library in question is fairly slow at compressing so it would put
quite a load on a web map server.

> Do you think there is a requirement for 1-bit IMAGEMODE?  We've noticed an
> increase in demand for geo-referencing (and viewing/"web publishing") of
> scanned drawings.

I haven't run into much of this myself, but it could in theory be added into
GDAL.  Likely this would be done as an 'IMAGEMODE PC256' where only 2 of the
256 possible colours are actually utilized and then output through GDAL to
GeoTIFF or something similar with FORMATOPTIONS forcing it to 1bit, perhaps
even using CCITT (fax) compression.

If someone whats this badly please let me know.  I would be willing to
incorporate the GDAL side support if someone will do the testing.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam,
warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent