Converting TIFF image to Fax Group 3 format

Converting TIFF image to Fax Group 3 format

I have a Tiff image and I need to convert that image to CCITT Group 3 and
4 formats.I found a lots of tutorials but in vain.I am unable to succeed
in getting the proper compression type.So where can i find the relevant
snippet or tutorials to do the same?can i find a samll snippet to do the
same