Move the field formatting (string or partial hex representation) in a function (overloading possible for user-definded fields).

If the resolution is not stored in the image passed in parameter, try to load the resolution from the NIST object

If the compression algorithme is already stored in the GCA field, it will be retured. If the value can't be decoded, a KeyError is raised

Store the file name in the self.filename variable, and the complete path in the self.fileuri variable

Rename the functions set_name() and get_name() to set_identifier() and get_identifier(), and move in the 'traditional' module.

move the conversion of FS, GS, RS and US fields to printable characters into the printableFieldSeparator() function