</td><td>Type of TIFF data, only set if FILE_TYPE is TIFF.  Valid values
    are APP1, APP3, TIFF, CR2, MRW, JP2, JPX, NEF, PEF, ORF, DNG, etc.</td></tr>

<tr><td>Validate</td><td>Flag to do extra validation checks</td></tr>

<tr><td>VALUE</td><td>Hash of raw tag values keyed by tag key</td></tr>

<tr><td>WARNED_ONCE</td><td>Hash of warning messages that have been issued once already</td></tr>

<tr><td>WRITE_GROUPS</td><td>List of write groups in order of priority</td></tr>

<tr><td>WRITE_PRIORITY</td><td>H