I can import 70000 x 2MB TIFF images (~140GB) using
Image`ImportExportDump`ImageReadTIFF
in about 3 minutes based on @Szabolcs solution to this question by @Kagaratsch which is fantastic.
However, the image data is converted to floating point numbers <1.
Is there an option for Image`ImportExportDump`ImageReadTIFF which will preserve the original integer image data?
I tried using the options "Data", "Bit16", "Automatic" which returned $Failed.