2024/02/05

That a *.tiff file:

was specified in 1986 by a company later consumed by Adobe
was originally intended for scanner interop
starts with an 8-byte header that includes a 2-byte magic number, a 2-byte endianness flag, and a 4-byte pointer to the first Image File Directory entry
the max tiff size is 2^32 bytes due to the u32 pointer size
Each IFD starts with a u16 count of entries, then a sequence of 12-byte ields, then another 4-byte offset of the next IFD entry (0 = none)
each IFD entry (= “field”) has a 2-byte tag, 2 bytes of field type, 4-byte count, and 4-byte offset of the value(s) of the field.
values may occur pretty much anywhere in the file, even before the IFD
each “subfile” may have one of several encodings (e.g. black/white, grayscale, rgb, etc)