How to get the number of pages of a fax?

Question

Is there a way to know how many pages a certain fax is without actually sending it? I am working with fax server. The only way I can tell you can do this is sending or receiving it.

I know how to access the pages in .tif file. My body of the fax is kept either in a byte() or rtf string or whatever.  So is there a way that I can tell how many .tif pages a byte() or rtf string will be? How 8 x 11 pages will a string/rtf string will be?

Any Suggestions?
Thanks
apalcer