Auto deskew fails on some spreads

The scanner will then have to go in and manually de-skew the page that auto de-skew didn't catch. Also, auto de-skew will skew pages to an extreme angle, this happens on both blank and text pages.

Blank pages doesn't auto-deskew well. The easiest way to deal with this is to just turn off deskew of a blank page, since the cropped page will be all white regardless of how how badly it is skewed.

We think that pages with wide margins are messing up the auto-deskew algorithm. Hopefully we can fix this issue without slowing down the camera loop..

Here are a couple books with bad auto-deskew..
Some of the early pages in this book:
http://www.archive.org/details/stevensgenealogy00stev

The photo opposite the title page is skewed wrong on this one:
http://www.archive.org/details/genealogyhistory00alle

It turned out that biggest cause of deskew errors were pieces of bright white foamboard placed underneath the book, with was causing bitonalization to fail. A new version of scribeImageOps (in Scribe 1.2.1) should help with this.