2015.08.26 01:02 "Re: [Tiff] Large files under Windows", by Bob Friesenhahn
Please note that I have not actually tested the large file support. I have only verified compilation and that the libtiff test suite passes under MinGW 32 and 64-bit, 64-bit Cygwin, and 32/64-bit Unix systems.
I have now done some testing. I created a 25GB BigTIFF file using GraphicsMagick (using libtiff 4.0.4 and GraphicsMagick's own large file implementation). I then used 'tiffcp' compiled with 64-bit MinGW and -D__MSVCRT_VERSION__=0x800 to copy to a new file. Tests were run on tiffcp using tif_win32.c and tif_unix.c. A md5sum of the result computed the same between both implementations. I then extracted a rectangle from the huge image using GraphicsMagick and checked that it was an expected image.
I have not seen results from large image testing from anyone else. More testing is useful to make sure that the next libtiff release does not have unexpected issues.
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/