Convert Scanned Pages Into eReader eBook Format

I find myself being obsessed with eBooks lately — probably because
I’ve just entered the world. But while making my first steps, I keep
discovering new and impressive feats.


In the past, we’ve already talked about stripping Mobi and PRC files
of their DRM
protection (read: restriction), where to find free
eBooks, and reviewed
Calibre, quite possibly the best management suite.



This time, I’d like to talk about a problem I’ve had with some of my
eBooks, and a convenient (albeit improvised) solution. I’m talking about
displaying scanned or pre-formatted eBooks in a readable eReader eBook
format.

What’s The Fuss About?

Reading on an eReader is fantastic. You won’t hear me saying anything
negative in that area. But to be able to enjoy a good read, you first
need to be able to read the damn thing.


Normally, most eReaders come equipped with a zooming feature. A hit
of a button can take your text up to ridiculous point sizes. The only
problem is when you’ve got eBooks that are in fact only scans of paper
novels and not quite eReader eBook format. Being bitmap images, your
eReader cannot rescale the individual text areas, and you end up with A4
or A5 pages on a 5″ display.

A related problem occurs when you’ve got pre-formatted text. Resizing
of course works great, but your once perfect text alignments are now
screwed up. A great example are coding eBooks, where the alignment and
formatting of text go a great way to making it accessible in eReader
eBook format.

Cropping Your eBook – PDFill PDF Tools

Yes, the solution is as simple as that. We’re going to crop away
those unnecessary margins. If you look at you’re document, you’ll
probably notice that it has a ridiculous amount of whitespace at either
side. Sure, it looks fine and makes the document printer-friendly, but
if your document gets ’scaled to fit’, that’s one thing you don’t need.


If you’re on a Mac, you can just use Preview for the job. Same story
if you happen to have Adobe Acrobat Pro. There’s not a lot of freeware
that allows you to work those PDFs, but PDFill PDF Tools works just
fine.


Know that although the real PDFill suite is proprietary, PDF Tools is
complete free, for personal AND commercial use. No
need to worry about a watermark either.

In the application, be sure to highlight All pages.
Discovering the correct margin settings is trial and error – 1″ left and
right, and 1.2″ top and bottom works if you don’t mind losing the page
number.


Strange enough, this often suffices to make the document readable.
You also might want to adjust your eReader to a landscape view.

Taking Apart The Bitmaps

Sometimes the resulting document still doesn’t meet your
requirements. Your other option is a little more drastic, but it
continues where the previous method left of. Basically, what we’re going
to do is cut all our pages in two pieces – top and bottom – with
overlapping parts. First, we’re doing a double crop, and then we’ll need
to put all pages back together in the right other.


Start out by duplicating your document and putting
it in separate folders. Crop one of
the documents towards the top half, the other to the bottom.


Next, still using the same application, export the first (top)
document to a series of PNG images, and the second (bottom) document to
TIFF.

You’ll notice that you’ve got two identically named series of images,
with the only difference being the extension. You can now safely join
those two collections in one folder. If you sort the files by name,
you’ll notice that the pages have mixed perfectly (that’s because PNG
comes before TIFF in the alphabet).

Still using the same application, we can now join those images into
one PDF. The PNG/TIFF export alphabet trick has saved you a ton of time
moving the page halves into place.


Note that you can also use it if you’ve got a double scan (two pages,
side by side). First making a vertical, then a horizontal crop
separation.