Can i use a normal image scanner for fingerprint recognition?If yes tell me how

Try wetting the surface of the scanner, and using "frustrated total internal reflection" to achieve a scan - look it up ;-)

After you get the image, it's all software -- coming up with logic which recognizes that the fingertip will almost certainly be at a different angle than the original scan and will probably be stretched differently , may have dirt or cuts or other problems which keep you from getting a perfect scan of the fingerprint and only the fingerprint, and generally will be complicated to match against the stored image(s). There's a tradeoff between how reliably you want to reject the wrong fingerprint and how reliably you want to accept the right fingerprint.

I'd suggest starting by doing a literature search -- possibly a patent search -- to see what algorithms have previously been published. I believe that most fingerprint-based locks these days use a feature-extraction approach rather than attempting to do a full image-to-image match.