These are all the possible values for the IG_ISIS_TAG_PLANARCONFIGURATION tag.
IG_ISIS_PLANARCONFIG_LINE_PACK | Line pack. Color data for each pixel is stored in order by line. |
IG_ISIS_PLANARCONFIG_PAGE | Page. Color data for the entire page is stored by color plane. |
IG_ISIS_PLANARCONFIG_LINE_UNPACK | Line Unpack. Color data for each line is stored by color plane. |