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2010.05.10 09:35 "Increasing the number of files loadable through libtiff", by Simon R Proud
2010.05.10 13:27 "Re: Increasing the number of files loadable through libtiff", by Edward Lam
2010.05.10 15:30 "Re: Increasing the number of files loadable through libtiff", by Simon R Proud
2010.05.10 15:51 "Re: Increasing the number of files loadable through libtiff", by Bob Friesenhahn
2010.05.10 16:17 "Re: Increasing the number of files loadable through libtiff", by Olivier Paquet
2010.05.10 19:10 "Re: Increasing the number of files loadable through libtiff", by Bob Friesenhahn
2010.05.10 20:07 "Re: Increasing the number of files loadable through libtiff", by Olivier Paquet
2010.05.10 14:01 "Re: Increasing the number of files loadable through libtiff", by Olivier Paquet

2010.05.10 15:30 "Re: Increasing the number of files loadable through libtiff", by Simon R Proud

Edward and Olivier, thanks for your replies. I used the info you gave me and
have fixed it now.

>>If it's the same as that last thread then your problem is probably not
>>reading the files

The problem occured at the call to TIFFOpen, not when actually
reading/writing to files.

>>- Examine the underlying cause of your error. Are you exceeding the
>>maximum number of file handles allowed?

This was the first cause of the error. I had a limit of 1024 and was trying
to open ~5000!
With that fixed the error persisted, though. But:
>>- TIFFOpen() flags: Use "m" to disable memory mapping, and probably "C" to
>>enable strip chopping. See
>>http://www.remotesensing.org/libtiff/man/TIFFOpen.3tiff.html 

This fixed it. I now run with the "rmC" flags and it is successfull, even
when loading a combined TIFF image set of larger size than the system
memory.

Out of interest: Is there any reason why memory mapping is enabled by
default? Enabling it causes problems like the ones I have been having and,
at least in my case, offers no speed advantage.


Thanks again for the help. The problem can be regarded as solved.


Simon R. Proud wrote:
> Hi all, some time ago I posted a thread about not being able to load
> large numbers of TIFFs using TiffOpen (
> http://www.asmail.be/msg0054686850.html ), for some reason I can't
> reply to that now. Anyway, I have now hit a similar problem again. I
> need to open a large number of TIFFs at once (totalling ~18Gb), but
> only have 16Gb of memory. Is there any way to overcome this and be
> able to open all files simultaneously? I've tried fiddling with the
> numerous TIFFOpen options ("rM", "rCm", "rcm" etc) but have had no
> luck.
> 
> I only need to read one scanline at a time (which for all files would
> total about 20Mb!), so don't see that memory for the entire file is
> required. Any ideas, assistance, etc? Apologies if this is a very
> basic query, I'm something of a novice programmer.
> 
> Thanks. Simon.
> 
> _______________________________________________ Tiff mailing list:
> Tiff@lists.maptools.org 
> http://lists.maptools.org/mailman/listinfo/tiff 
> http://www.remotesensing.org/libtiff/ 

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