I realised that what I was asking would necessitate a lot of rewriting of other code in UPP. I have tested this and it works with an image of 3.45GB.
Can we make this change in the SVN please?
Cheers,
Nick
It is in svn now. I think I will add direct support to Stream soon.
I also think that you might consider whether you really need to store the image expanded. Note that you can e.g. draw compressed TIFF in Paint with some effort. Or you can rescale it to something smaller without decompressing original.