View Single Post
Old 06-30-2009, 07:04 PM
STH STH is offline
Global Mapper User
 
Join Date: Oct 2007
Location: Norway
Posts: 384
Thanks: 10
Thanked 8 Times in 8 Posts
Default

Thought I would share my advice, but I`m sure you might be aware most of them:

1. Use a Map Catalogue containing all the images
2. When exporting to ECW it will create an image as large as the bounding box of all the images - so try to see if the bounding box is very large. Remeber ECW will also try to "compress" all lines outside your actual images inside the bounding box. You can get a very large bounding box in atleast two cases:
2A: for instance if you have two areas far away from each other.
2B: If one or more images are incorrectly georeferenced (meaning one image will end up in coordinatespace 0,0 while the rest will be at the correct place - thus creating a bounding box from 0,0 to 500000, 500000 or whatever your coordinates are)
3. GlobalMapper for the moment only use one core for processing, ER Mapper which costs more money will use all available processors decreasing the time
4. Networks are unstable - so my advice is to have the files available locally or on a USB/firewire disk so they are always available - I have experienced conversion stopping after 2 days just because the network was down for 1 sec - NEVER again !
5. ECW files generate temp-files in the same catalogue as the output - so I suggest the output file to be on a local or USB/firewire (not the same as the input files) for fastest times
6. Multiple instances running once. I have experienced problems running two instances of GlobalMapper on the SAME dataset but I guess you are running each instance of GlobalMapper on completely different files? (ie no overlapping etc..).
7. Turn off anti-aliasing/fill small gaps to speed up processing.
8. Perhaps you can try a test with smaller resolution first, for instance 50m, just to see if it manages to create "something" and that there is nothing wrong with the input files?
9. Running multiple instances eat RAM - remember the limitation on Win 32 bit and your 2GB of RAM. Try to start only one instance of GlobalMapper and do one county and if it "hangs" for a long time , check the amount of used RAM and the Windows SWAP file to see if it is swapping to disk all the time or not.

Sorry for the long reply, however I did not have time to shorten it Let us know how it goes.

GlobalMapper: Will the new v11 be able to use more than 4GB ram and more CPUs when creating ECWs or is the number of CPUs a limitation on the ECW-dll itself?
__________________
Sincerely yours

Sigbjørn
Norway

Last edited by STH; 06-30-2009 at 07:10 PM. Reason: Made it more readable
Reply With Quote