Reference number for the next call to DF24getimage
Purpose
Specifies the reference number of the next image to be read when DF24getimage is next called.
Return value
Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
Description
DF24readref is commonly used in conjunction with DFANlablist, which returns a list of labels for a given tag together with their reference numbers. It provides a means of non-sequentially accessing 24-bit raster images in a file.
There is no guarantee that reference numbers appear in sequence in an HDF file. Therefore, it is not safe to assume that a reference number is the index of an image.