rewriteDirectory(t) writes modified
metadata (tag) data to an existing directory. Use this function when you want to
change the value of a tag in an existing image file directory.
This function corresponds to the TIFFRewriteDirectory function
in the LibTIFF C API. To use this function, you must be familiar with the TIFF
specification and technical notes. View this documentation at LibTIFF - TIFF Library and Utilities.