PDF tricks for book scanning

Extract images from a PDF

Probably part of TeXLive.

pdfimages -all <pdffile> <outputname>

Convert JPG images to PDF

Uses ImageMagick.

convert <srcimage>.jpg -auto-orient <outimage>.pdf

Concatenate PDFs

Probably part of TeXLive.

pdfunite <pdf_1> <pdf_2> .. <pdf_N> final.pdf