How I scan documents with Scanner Pro
I’ve been going on about scanning software for iOS and Android lately, and there’s a reason for that: I currently need that kind of software. A new semester has started, and that means lots of books that the great powers of publishing have deemed unworthy of proper digitalization. This semester it’s particularly bad, and I’m going to find myself scanning quite a few pages before I can safely bring only my iPad to lectures.
The more pages you need to scan, the better – and faster – your system needs to be. There are people who have made bookscanning into a science, and my system is a bit less sophisticated than that, but it still works quite well.
The center of the system is my DSLR. Using a Good camera for scanning has several advantages over using a mobile device camera, and it’s even faster than using most consumer level document scanners. I use manual mode for taking the pictures, and the reason is that the resulting quality is very dependent on the input images (duh). I use ISO 400, aperture F.8.0, flash, and 1/60 shutter speed. A high aperture level (which means a small aperture opening) gives you a greater depth of field, which is great for scanning books where the curvature of the page means that not all the text is the same distance from the camera. It does let in less light, but the ISO value, shutter speed, and flash use compensates, and the use of flash both gives an even light and removes the need for an external light. For glossy paper, the aperture value additionally allows you to take the photos at a slight angle, preventing the flash from reflecting in the paper and burning out part of the text.
My book holder is designed to hold a book flat. “Professional” camera-based book scanners often use a book holder designed to hold books with a 90 degree angle between pages, and use two cameras – one for each page. Since I don’t have that luxury, I use some large paper clips attached to a piece of cardboard (the box from a PC monitor) to clamp the book down as flat as possible. Depending on the size of the page and the font size, even my iPad 2’s screen resolution is often enough to view two pages side by side on the screen, without zooming. If that’s the case, I photograph both opposing pages at once, turning each double page into a single document page. If not, I photograph one at a time.
With all pages photographed, I run them through Irfanview on my computer in order to compress them. I put them back on the SD card from the camera and make sure to preserve EXIF data, otherwise the iPad will have trouble importing them. I import all the photos using the Camera Connection Kit, and then use the bulk mode in Scanner Pro to import them all into the app. This brings up a screen where you adjust crop and rotation on pages one by one, and this is where Scanner Pro really shines: the page processing is so fast that you don’t have to wait for each page to process. You simple fix crop and rotation page by page, and when you’re done doing that to all the pages, the document is processed. Compressing the images before running them through the app is however crucial to avoid the app crashing, and right now I have to photograph the pages backwards to compensate for Scanner Pro importing them backwards.
The total time to scan a book varies. A 100 page book I scanned yesterday took me 35 minutes from start to finish, and that was while watching TV. At the end of those 35 minutes, I had a PDF version of the book in my Dropbox folder. The finished result looks something like this:
Now you might say that this is a process for pirates, but that’s not true. I literally can’t fit 1/3 of my books in my bag, let alone any of the loose documents. Having everything in digital form on a tablet is a massive advantage, and by syncing via Dropbox I even have everything accessible on any device, any time.