2022.12.10 11:29 "Re: [Tiff] How to write multi-file TIFFs", by John
Yes, TIFF files have two page dimensions.
You can put directories one after the other with TIFFWriteDirectory() and you'll get a simple multipage document, conceptually like a PDF. This is the dimension you'll find most widely supported in things like GIMP.
Hanging off each top level "page" you can also have subifds. You need extra API to read these and they are not so widely used. The biggest application I've found is in OME-TIFF which stores each channel (so RGB plus various fluorescence and confocal layers) as a separate top-level mono image, then uses subifds to hold pyramid levels.
Unless you really need subifds, I'd stick to just using TIFFWriteDirectory(). Just call it at the end of each page, no need for TIFFCreateDirectory().