Readdle's Scanner Pro has been my favorite iOS scanner app for over a year now:
...for the professional who runs a small business, or individuals who do scan documents, just not so many every day, I’d seriously suggest considering Scanner Pro on the new iPad. The device’s camera will give you decent images — especially with good lightning and background — and the app works with the services many are already using for document storage and archival.
I have been experimenting with different paperless systems (I still haven't settled on a specific one), but Scanner Pro was and will remain at the core of my mobile scanning workflow. Every day when I get home, I fire up Readdle's app on my iPhone/iPad, take the receipts and paper documents I've collected during the day, scan them using Scanner Pro, and send them to one of the services built into the app (such as personal favorites Evernote and Dropbox). With today's 4.5 update, which I have been testing, Scanner Pro gets even faster and more intuitive thanks to real-time border detection.
It used to be that Scanner Pro let you take a photo and adjust borders for cropping a document by manually moving a series of controls around the area you wanted to scan. Scanner Pro did a decent job at guessing where it should place the borders, but they still needed tweaking most of the time. In version 4.5, the Readdle team has completely reworked the algorithm behind border detection to make it smarter and bringing it into the camera view as well.
When taking a picture of a document, Scanner Pro 4.5 will overlay borders directly on top of the object, with impressive results. In my tests (a screenshot of which you can see above) Scanner Pro capably recognized borders of paper documents against dark and light backgrounds, in both normal and low-light conditions. Because borders are detected in real time, you can move objects or place other items in the shot and view borders update within a fraction of a second without leaving the camera view. It's incredibly cool – but, fortunately considering the app's utilitarian goal, also efficient.
While Scanner Pro tries to automatically detect borders and offer its best take in the Save screen, you can still tap Back to adjust borders manually. This is a welcome option – the app now defaults to the Save screen after a picture has been taken and processed, but you still want to retain manual control in case the new border detection algorithm doesn't work properly.
It's not a replacement for full-featured hardware such as Fujitsu's ScanSnap, but for people who, like me, don't have exorbitant amounts of paper to digitize every day, Readdle's Scanner Pro remains a reliable, powerful iOS scanner app with tons of useful options. The new automatic border detection is a simple feature – but a handy one that's uniquely suited for the iOS camera.
Scanner Pro 4.5 is available on the App Store.