I seem to recall that you get a misleading "out of memory" exception when
the format of the image file is wrong, so make sure you can load a smaller
image of the exact same type, and if not, look for other causes of the
problem.

While Michael made a good point about the misleading errors, if your
TIFF is actually 2GB it's not necessarily surprising that you would get
an "out of memory" error trying to load it.

For sure, there's no way you'd be able to load that under 32-bit
Windows.  If I recall correctly, even under 64-bit Windows, .NET is
still 32-bit though, and can't deal with objects larger than 2GB.

If your question hasn't been answered either by Michael's post or the
above, you should probably be more specific about the exact environment
you're using to attempt this.

Yes, but AFAIK there's nothing in .NET that would do this for you.
You'll have to parse the TIFF yourself and extract the specific data you
want for each sub-image.

Pete