|Extension TIFF Tag PageNumber|
TIFF Tag Reference
TIFF Tag PageNumber
The page number of the page from which this image was scanned.
This field is used to specify page numbers of a multiple page (e.g. facsimile) document. PageNumber is the page number; PageNumber is the total number of pages in the document. If PageNumber is 0, the total number of pages in the document is not available.
Pages need not appear in numerical order.
The first page is numbered 0 (zero).
We've seen reports of some broken applications reversing the PageNumber and PageNumber values.