[mapserver-users] preparing orthos for Mapserver?

[Andrea Aime]

On Sat, Oct 5, 2013 at 4:21 PM, Frank Warmerdam <warmerdam at pobox.com> wrote:

> Great advice from Jukka, and I'd just note that GDAL
> *will* efficiently pull out reduced resolution images on
> the fly without overviews if you have a file organized
> with a one scanline block even in the year 2013.  For
> map serving you are still much better off for several
> reasons with the tiles+overviews approach, but I do
> love the properly that a one-block-scanline file can be
> quickly subsamled by viewer applications like OpenEV
> and QGIS.
>

Hi Frank,
this is quite interesting. Can you elaborate a bit of what "one block
scanline" means?
E.g., what is the actual tiling structure of this file?
Does presence of compression affect the ability to do the subsampling?
How about quality of the output? (e.g., is GDAL reading one pixel every N
to generate
the reduced resolution version?)

Cheers
Andrea

-- 
==
Our support, Your Success! Visit http://opensdi.geo-solutions.it for more
information.
==

Ing. Andrea Aime
@geowolf
Technical Lead

GeoSolutions S.A.S.
Via Poggio alle Viti 1187
55054  Massarosa (LU)
Italy
phone: +39 0584 962313
fax: +39 0584 1660272
mob: +39  339 8844549

http://www.geo-solutions.it
http://twitter.com/geosolutions_it

-------------------------------------------------------
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/mapserver-users/attachments/20131006/4c1d5f4b/attachment.html>