Just to give people a rough guide on this: internally FLIRT will
represent the image uncompressed with floats (32 bits per pixel)
which, in this case would be 1000x1000x500x4 bytes for one image,
or 1.9GB. Now it is necessary to store an input and a reference
image normally, plus some temporary images which are created
at different points in the calculations, so I'd expect that 3*1.9GB
or 5.7GB would be what it needs to run for most of the time. I
think the extra comes at some very brief points in the process
which might be a bit inefficient, so we'll look at that. But I would
say that the rule of thumb is you need between 3 and 5 times
the amount of memory that one image takes at present, although
it will spend most of the time using somewhere between 2 and 3
times one image's worth of memory.
I hope this is helpful.
All the best,
On 19 Aug 2009, at 09:44, Richard Green wrote:
> Sorry, my message was meant to come up as part of a previous thread
> that had
> more details in it.
> The images are nifti format, ~60MB compressed, ~440MB uncompressed,
> 1000x1000x500, unsigned char 8bpp. I'm running 64bit Ubuntu.
> I'd previously done my registrations on reduced resolution images
> but wanted
> to compare to full res.