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.