Le portail francophone de la géomatique

Bonjour,
J'ai posé la même question sur forum mapguide.... histoire de relancer la discussion.
Et puis j'ai cherché de nouveau dans les anciens posts quelques infos à propos de cette problématique.

L'inconvénient majeur de mapguide 6.5 reste qu'une bonne partie du code est de qualité inégale, en particulier l'incorporation du format Mr sid rendant l'usage de ce format très délicat....

D'après les réponses des utilisateurs je tombe sur une réponse différente, en effet le problème principal reste la capacité du serveur à gérer au niveau ressource un très gros fichier....

Voilà la synthèse (en anglais....approximatif) de la discussion :    

http://discussion.autodesk.com/thread.j … dID=582891


Re: Map Serveur 6.5 ECW optimisation
Sorry, but i will be more clever to search forum before....

anyway i find some answer here :

http://discussion.autodesk.com/thread.j … ID=4991523

http://discussion.autodesk.com/thread.j … ID=2019696

# The First Scenario is better, a maximum of 50 to 100 meg per file is enough for the server.

# To optimize the scenery it could be better like explain on the other post to work on the scale and decrease the dept of the imagery as the scale is higher.

If you have other experience to share you could alway give me yours thinking about this answers ! We are newcomer in the mapguide universe. Cordially JM MASSOU

Reply From: suzannem
Date: Jan/13/06 - 01:10 (GMT)
Reply
Re: Large ewc files
We are having trouble with the response times for a 5GB image. It is taking almost 2 minutes to zoom and pan around! I noticed your message and was wondering if you could provide details of the IT setup for your MapGuide server etc.???




Reply From: Andy Morsell
Date: Jan/13/06 - 07:55 (GMT)
Reply
Re: Large ewc files
That's a huge image for MapGuide to have to deal with on a request by
request basis, which is what is happening with each zoom and pan. You
should tile it into many smaller pieces (but keep them in ECW format) and
use Raster Image Workshop to create a catalog of them. Try 50 to 100 MB per
tile to see how your performance is.



Reply From: Carl Von Stetten
Date: Oct/03/05 - 20:51 (GMT)
Reply
Re: New Server specs?
Tim,

Not necesssarily. If you process them through the MapGuide Raster Workshop to add tiling, it would help greatly. Also important is what zoom scales you make the rasters visible from.

In our application, we made the 6inch/pixel imagery available only when zoomed in closer than 1:1000. As you zoom out from there, we use subsampled versions of the images to show less and less detail.

Here is our layer scheme:

* 1:1 to 1:1000 - 0.5ft/pixel
* 1:1000 to 1:5000 - 1ft/pixel
* 1:5000 to 1:10000 - 5ft/pixel
* 1:10000 to 1:20000 - 10ft/pixel
* 1:20000 to 1:40000 - 20ft/pixel
* 1:40000 to 1:70000 - 40ft/pixel
* 1:70000 to 1:100000 - 80ft/pixel

We used Raster Workshop to generate each of the original 0.5ft/pixel images into the various low-res versions. Each successive subsample shrinks the resulting file sizes dramatically. Here are the total file storage requirements for our 561 color TIFF images:

* 0.5ft/pixel - 150GB
* 1ft/pixel - 38GB
* 5ft/pixel - 1.6GB
* 10ft/pixel - 411MB
* 20ft/pixel - 124MB
* 40ft/pixel - 25MB
* 80ft/pixel - 7MB
* Grand Total - 190GB

HTH,
Carl

Dernière modification par massou (Wed 13 June 2007 00:58)