I've gotten nice results with BRISS when all the pages are the same, but for books with irregular patterns (and weak scans) BRISS gets a bit confused. I've had the better luck with:
Code:
pdfcrop --debug in.pdf out.pdf
This file is distributed with texlive-extra-utils on linux, renamed from pdfcrop.pl
It seems to live here:
http://www.ctan.org/tex-archive/support/pdfcrop/