Specifies data format to be used by IG_DIB_area_get and IG_DIB_area_set functions.

Values:

IG_DIB_AREA_RAW	This value has been deprecated and will be removed from the public API in a future release.
IG_DIB_AREA_DIB	Get or set the data in standard uncompressed DIB format. Each row is padded to a multiple of 4 bytes length. 1-bit pixels are returned 8 to the byte, most significant bit first. 4-bit pixels are returned 2 to the byte, similarly left justified. 24-bit pixels are returned 3 bytes per pixel, ordered Blue-Green-Red.
IG_DIB_AREA_UNPACKED	Get or set the data using 1 pixel per byte, or 3 bytes for a 24-bit pixel, ordered Blue-Green-Red. Each 1-bit or 4-bit pixel will be returned right justified in a single byte, padded with zeroes in the most significant bits of the byte.