Error in Exporting an ECW

adrufadruf Global Mapper UserPosts: 17Trusted User
edited May 2010 in Raster Data
Hi, I'm new to the forum and I'm having an issue with Global Mapper 10. I have a large number of MrSid tiles (~6GB, 1700 tiles) that I was able to successfully export to ECW files using "Batch Convert/Reproject." However, when I go through the mosaic process of these tiles (via "Export Raster & Data Elevation Data" > "Export ECW File...") to generate a single ECW, I receive the following error message:

Unable to generate ECW file C:\XXX\Desktop\Kent\Kent.ecw.
An error has occurred: Error 46 "Could not allocate enough memory" file "" line 0
ECWOverlay.cpp - 1573
Build Time: May 15 2009 11:02:31

My settings in the "ECW Export Options" are as follows:

General Tab
Target Compression Ratio: 1:1
Checked Generate World File
Checked Generate Projection File
Checked Make Background Pixels Transparent

Gridding Tab
Selected "No Grid -- Just One Export File Per Input File"

All other options were left as default.
Any idea what might be the root cause and how to fix the error? Thank you!

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2010
    The error is coming from the ECW library that we use and may be related to the size of data being exported. Do you have a 64-bit Windows computer that you might be able to give a 64-bit v11 trial a try on to see if the size issue can be circumvented in a 64-bit environment?

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • adrufadruf Global Mapper User Posts: 17Trusted User
    edited April 2010
    Thanks, Mike, for your immediate response! My office has 32-bit Windows running on 64-bit machines. I work for a University and I.T. has informed me they do not support 64-bit Windows; So we've found ourselves in this predicament. The shame is we bought the 64-bit Machines for the express purpose of processing. So the simple answer to your question is no, we don't.

    Is there a way to bypass the Windows Operating System and tap into the 64-bit processing power of our machines some other way? If not, do you have any other recommendations? Again, thanks for your help.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2010
    There is a way to allow use of up to 3GB of memory per process rather than the standard 2GB in 32-bit XP. See http://www.finitesolutions.com/Support/Enabling3GB/tabid/70/Default.aspx for instructions on doing this. There's a chance this may be enough to help you.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • STHSTH Global Mapper User Posts: 434Trusted User
    edited April 2010
    One tip. I havent had the time to try it myself yet. However you can try to install a 64-bit operating system in a virtual machine (like Virtualbox or vmware) on your 32-bit operating system. The only thing is you might have to enable something in the BIOS and check that your computer supports this.

    Here is one article mentioning it, I didnt find the one I read some time ago regarding this. Please let us know how it goes:

    http://www.petri.co.il/virtual_run_a_64_bit_guest_operating_system_in_vmware.htm

    and also this link:
    http://stackoverflow.com/questions/56124/can-i-run-a-64-bit-vmware-image-on-a-32-bit-machine
  • adrufadruf Global Mapper User Posts: 17Trusted User
    edited April 2010
    Thank you both for your responses!

    Mike,
    I allowed the 3GB of memory per process and that did not work. I received the exact same error message in return. So, feeling gutsy, I upped the memory to allow 8GB per process - this, also, was not successful and returned the same error message as before.

    Just a shot in the dark, but could the lack of memory be a reference to physical memory? If so, how much would I need to run a process on 6GB of data? Any other suggestions? Thanks so much!

    STH,
    I read the article and tested my computers' 64-bit Virtual Machine ability. I am happy to inform you that my computer can run the virtual operating system, but I think this is an avenue I will go down last because of the issue I found with Mike's solution. Thanks so much for your help and if you have any other suggestions, I'd truly appreciate those as well.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2010
    Regardless of what you set the memory to, you'll never be able to use more than 3GB of memory per process on a 32-bit XP installation. In 32-bit systems each application has a maximum 4GB memory space (32-bits can address 4GB of memory), and the system requires at least 1GB of that memory space for its stuff, leaving the application with a maximum of 3GB of memory that can possibly be used.

    You need 64-bit Windows to increase addressable memory space and thus gain access to memory over 3GB (there is a limit as well in 64-bit Windows, but no system is close to having that much memory yet).

    One other thing to try is getting the latest 32-bit v11 trial and giving it a try in case the latest ECW library that v11 uses reduce the memory required. If you contact me at support@globalmapper.com I'll provide a trial key to try out the full functionality of the latest v11 trial release.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • adrufadruf Global Mapper User Posts: 17Trusted User
    edited April 2010
    Mike,
    Thanks for your advice, what you say about the maximum of 3GB of memory per process makes a lot of sense. I downloaded the latest v11 trial of GM and using the trial key you gave me I was able to test the fully functional 32-bit version. Unfortunately upon export I returned the same error. Any other suggestions? I am able to export the tiles in clusters of about 50 at a time without receiving the error message. I wonder why 32-bit cannot accomplish large export tasks. Shouldn't it just process them slowly? Is there any way I can reduce the memory required in my current GM v10? I clearly don't know enough about the technical aspect of memory usage, but thanks for all the support!

    STH,
    I installed VMware on my computer to test 64-bit processing, but when I tried to access the server homepage, the site wasn't recognized by my brower so I couldn't initiate the server. The VMware seems a bit more advanced than I'm comfortable with at first and so I uninstalled it. If you have any troubleshooting advice, I'd be glad to reinstall it and give it another go.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2010
    I may have neglected to mention this, but do you have your input data organized in map catalogs (use File->Create New Map Catalog menu command to do this)? Using map catalogs will significantly reduce memory utilization in cases of using large amounts of files. If you weren't already using map catalogs this may be the solution.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • adrufadruf Global Mapper User Posts: 17Trusted User
    edited April 2010
    Yes, I have been using map catalog to load my data. Thanks for the suggestion though!
  • STHSTH Global Mapper User Posts: 434Trusted User
    edited April 2010
    How much RAM do you have installed?

    If you have 4 GB it will not help much to switch to the 64-bit guest OS due to the 32-bit OS taking up some RAM by itself (perhaps 1GB) leaving 3 GB left for the 64-bit OS... which is the same as before. However if you can run the 64-bit guest OS and install additional 4-8 GB (so 8-12GB of RAM in total) and you can use this in the guest OS then it will work better.

    However I am not sure if it is possible to use more RAM in a Guest OS of a 32-bit environment.

    Sorry for being a bit "technical" however thats the only way I can think of to solve this.

    Although the easiest would be to get them to install a 64-bit OS, as you write you bought them and therefore it is no logic in not having the correct OS installed. Although you might have to find drivers and solve som issues related to the 64-bit OS yourself (without support from your local IT-guys) the advantages of more RAM are superior!
  • adrufadruf Global Mapper User Posts: 17Trusted User
    edited May 2010
    Just want to thank you both for all of your help and let you know I was able to resolve the issue.

    It turns out a few of my tiles were not spatially referenced. So when I loaded the 1700 tiles, there were 11 of them that appeared in "no-man's land" if you will. I removed these 11 tiles, tried the export and about 12 hours later (with no errors) I had a fully-functional ECW. I am assuming the non-spatially referenced tiles and the spatially referenced tiles were so vastly far apart that GM was immediately noticing that it would not be capable of exporting so large of a file... perhaps!

    Anyway, thanks for all your suggestions. Seems like I should have noticed this a bit earlier.
Sign In or Register to comment.