Can a digital watermark be still extracted from the reprinted digital watermarked image? If I'm able to extract a watermark from a printed watermarked image, will I be still able to extract the watermark information if I first scan the printed watermark image and reprint it (make a copy of printed watermarked image with high quality scanner and printer)?
Yes it can. But it's very difficult to resist the printing process. 

You can find useful information here:
http://jultika.oulu.fi/files/isbn9789526200583.pdf