GDF GEt Image Slot IS I Slot number Output ERROR L Error flag OutputGDF_GEIS returns a unique image slot number IS, for further use in all other GDF_xxxx routines.
GDF CLose Image Slot IS I Slot number Input ERROR L Error flag OutputGDF_CLIS close an image slot IS, disconnecting all associated memory slot after flushing all pending updates on the image. The image slot IS stays reserved, but available for further use.
GDF FRee Image Slot IS I Slot number Input ERROR L Error flag OutputGDF_CLIS free an image slot IS, disconnecting all associated memory slot after flushing all pending updates on the image. The image slot IS should no longer be referenced in any call after this operation.
GDF STatus of Image Slot IS I Slot number InputReturn status of slot: -1 No such slot, 0 Empty (Not allocated), 1 Read (Opened for ReadOnly), 2 Full (Allocated but not opened), 3 Write (Opened for ReadWrite).