TIFF Image File Directories are comprised of a table of field descriptors of the form shown below. The table is sorted in ascending order by tag. The values associated with each entry are disjoint and may appear anywhere in the file (so long as they are placed on a word boundary). If the value is 4 bytes or less, then it is placed in the offset field to save space. If the value is less than 4 bytes, it is left-justified in the offset field.
