[gdal-dev] Q: on gdalwarp of ecw file

[Jukka Rahkonen]

Jan Hartmann <j.l.h.hartmann <at> uva.nl> writes:

> 
> 
>     Thanks Jukka, very
>       informative. I'll start with jpeg compressed tiffs and will do
>       additional tests next year. I'm on a Cloud environment nowadays,
>       so it's easy to set up clean VMs for testing. Any suggestions for
>       experiments with different raster formats would be very welcome.
>       Jan


Here is a fresh table comparing resampling methods and cgi vs. fast-cgi with
Mapserver and with raster map data. 
http://latuviitta.org/Apps4Finland-2012/documents/Taustakartta_WMS_kapasiteetti.html

Titles are in Finnish but you can make it with this lexicon
näytteitä=samples
vasteaika=response time
keskiarvo=mean
kuvaa/sek=images per second (800x600 pixels)

Thus you can get either 17.3 images per second or 63.7 from the same source data
just be changing Mapserver/GDAL options. Naturally the quality is not the same
which is another prove for considering the whole system instead of optimizing a
single piece of it.  By the way, numbers show that "cgi slow-fast-cgi fast" is
not the whole truth either. If there is lot of computing with bilinear or
average resampling the difference in speed is nominal and cgi is much more
stable - look at then maximum response time field.

-Jukka-