I tried this free app, Docr
, to scan a book.
It automatically detected a curled page boundary & still manually adjustable.
Then, dewarped / converted it to a flat page.
Tried its magic shadow removal & color enhance function.
Saved as PDF and annotate
Email it out, sync / export to iCloud Drive, or upload to Google Drive, Dropbox, Box.net …etc.
No annoying ads in the app.