Lists all RAS tag identifiers.

Values:

IGMDTAG_ID_RAS_FORMAT	RAS metadata format identifier.
IGMDTAG_ID_RAS_MAGIC	RAS magic value.
IGMDTAG_ID_RAS_WIDTH	Image width.
IGMDTAG_ID_RAS_HEIGHT	Image height.
IGMDTAG_ID_RAS_DEPTH	Image depth.
IGMDTAG_ID_RAS_LENGTH	Length of the image data (which is the length of the file minus the length of the header and colormap).
IGMDTAG_ID_RAS_TYPE	RAS format type.
IGMDTAG_ID_RAS_COLOR_MAP_TYPE	Color map type.
IGMDTAG_ID_RAS_COLOR_MAP_LENGTH	Color map length.