ECW generation stopped

SigTill

After a couple of days humping along nicely the generation of my ECW is now stuck on 89% and have been that for at least 24 hours. GlobalMapper still use all the CPU, but the temp-filesizes does not increase in size. So I assume the whole process have stopped, even though GlobalMapper does not crash or give me an error. So far it have generated 23 files, ranging from size 0 to 3,2GB. With a total of 8.5GB for all the files. It use a little above 1GB of RAM (perhaps 1024MB is the limitation of GlobalMapper?) and the PageFile is filled with 2.17GB of data).

So to my question:
1. Is it possible to implement a "resume" option to finish where the last ECW-generation failed? Would be nice since my dataset consists of 250GB uncompressed GeoTIFF.
2. Is it possible to find the error? Why does GlobalMapper suddenly stop? Some error-reporting would be nice. All files load up in GlobalMapper and shows nicely, but I can not guarantee that one of the files are corrupt in some way. Its just difficult to find which one and fix it.
3. Have anyone created files this big with GlobalMapper before?

I guess I just have to try to start over again and see if it stops at the same time/space spent.

global_mapper

It sounds like you are gridding your export, which is good because you can resume those. You just need to kill Global Mapper, then go to the export folder and delete the most recent ECW file as it is likely corrupt or incomplete.

Then, start the export again with the exact same options, except on the Gridding tab check the option at the bottom to skip existing files. This should resume the export with the file that you just deleted.

It sounds like some memory cache internal to the ECW library has filled up, slowing things to a crawl. Restarting the export should hopefully fix this issue (unless it really is corruption in one of the TIFF files). We don't have any control over what is done in the ECW library. Global Mapper itself is limited to 2GB of memory usage on 32-bit Windows (or 4GB if you have 64-bit XP or Vista). If the ECW library actually reported an error we would show it, but if it just gets really slow or locks up internally we don't know about that.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

STH

By gridding you mean exporting to several ECW-files by using the Gridding option I guess? I do not use this option, but try to make one large file instead.

The filenames are called for instance ecw1b905cc7, ecw13db3e77 etc.

I tried to check the "resume" option - however it says:

"No compatible and exportable data is available for export within the specified export bounds."

I will now try to export with the gridding option, and try to export on another machine without gridding to see if there is a problem with the current hardware. Will continue this thread as soon as I know more, but I assume I have hit the 2GB memory limit of GlobalMapper (not just GlobalMapper, I guess all software for 32-bit systems have a limitation of 2GB, at least I heard the same limit is present in Photoshop).

global_mapper

When you said it had generated 23 files I just assumed that you meant 23 final ECW files, not the temporary files with names like ecw1b905cc7. Those files are created by the ECW library as it does the export. There is not any way to resume an export of a single ECW file that was aborted or crashed.

It does sound like perhaps you have hit the 2GB limit between the memory used by Global Mapper and whatever is used internally by the ECW library itself.

One other thing to check is that you have sufficient free space on your disk for the operation. It sounds like you might need 20GB or so free space for all of the temporary files used during the export and the final ECW file itself.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com