Specifies types of vector extra data associated with a HIGEAR image.
Values:
| IG_EXTRA_DATA_ARTX | Type of extra data is ARTX. |
| IG_EXTRA_DATA_CAD | Type of extra data is CAD. |
| IG_EXTRA_DATA_PDF | Type of extra data is PDF. |
| IG_EXTRA_DATA_POSTSCRIPT | Type of extra data is PostScript. |
| IG_EXTRA_DATA_XPS | Type of extra data is XPS. |